Preface:
If you're not a performance user, or you are trying to keep your costs low, AMD is a better choice right now. Otherwise Intel is the way to go.
Regarding motherboards with integrated video, do NOT use motherboards with Intel integrated graphics (or at the very least, get a separate video card). Intel integrated graphics (and the drivers they use) are of such poor quality it will cause crashes with various programs, and actually slows the rest of the system down, even in normal every day tasks. Stick with either Nvidia or ATI integrated video (if you want integrated video), or use a Pci-E video card outright.
One final cost consideration: all things being equal, good quality motherboards for Intel cpu's tend to cost more ($30-$50 extra) compared to a similar board for an AMD cpu. Those trying to stay on a budget will want to keep that in mind.
Intel CPU recommendations
Totally avoid the Intel P4 (and Pentium D variant) cpu's, they are very old, run way too hot, and cost too much for the price/ performance level (a $50 AMD X2 will blow em out of the water and run much cooler to boot). The Celeron Conroe and Pentium E variants aren't horrible, but AMD cpu's at the same price point tend to perform a tad better, so for budget users you are much better off looking at AMD.
Be aware that the current LGA 775 and LGA 1156 heatsink mounts just BLOWS compared to the AMD AM2/AM3 type mount, and extreme caution should be used when working with it. Just adding or removing a heatsink off a LGA socket can damage the socket or heatsink mounts unless you are extremely careful.
Intel has 3 different platforms currently available.
Socket 775 with Core2 class processors - The current mainstream Intel platform. Its well proved, stable, but it's on the way out. Uses DDR2 or 3 ram depending on the board. For new systems, I'd skip socket 775 and move on to socket 1156.
Socket 1356 with I7 Cpu class processors - Extremely overpriced, but currently the highest performance option from Intel. Generally NOT worth the money now that the I5 is out. Uses DDR3 ram.
Socket 1156 with I5 or I3 Cpu class processors - This is the replacement platform for Socket 775. The I5 class cpus are faster then the Core series, and are only a little bit more spendy. Uses DDR3 ram. Avoid the hyper expensive models and stay under $300.
Socket 775 Boards:
The best choices in Core2 motherboards use an Intel chipset. Be advised that Intel in one of the most idiotic chipset / platform decisions in years (probably the worst since the early 8xx series fiascoes) decided to NOT include ANY native pata channels on their current ICH8 / ICH9 / ICH10 southbridges for the Core 2, forcing all the Intel chipset MB oem's to use 3rd party controllers (and these usually have lots of performance and compatibility issues) to provide this functionality. If you go with an Intel chipset, MAKE SURE to ONLY use sata hard drives and have at least one sata optical drive. If you have additional pata optical drives, its usually safe to stick them on the 3rd party controller. Usually this is only a problem for people trying to re-use old drives.
Avoid the Nvidia chipset boards, as the only advantage they offer over the Intel chipset boards is sli support, and sli generally is NOT worth it. Plus, the drivers for Nvidia boards tend be a lot rougher compared to Intel.
Make sure your board has official 1333 bus speed support (and not just the cheezy "OC" support). Almost all of the current Intel cpu's require this. Avoid older chipsets that don't support this (like any of the Intel chipsets prior to the P35/P45 series).
Gigabyte GA-EP45-UD3L Based on the Intel P45 chipset. Fairly cheap by Intel chipset standards. Features are fairly vanilla, 6 sata ports, lots of pci-e slots, and the IO plate offers an impressive 8 usb ports. Ethernet and audio are both realtek, so no wierd drivers to be concerned about there. The bios can be flashed right off a usb flash drive without needing to boot into dos (very handy!). Overclocking features appear to be very impressive as well. Stability is excellent, even while overclocked during heavy gaming or dvd encoding. This is my preferred board for Intel socket 775 cpu's.
Newest bios updates for this board can be found here.
Gigabyte GA-EP45-UD3R If you need firewire, this board is virtually identical to the above board, except it includes firewire and a extra 3rd party sata controller as well. The heatsink cooling is slightly improved as well. Usually runs about $10-15 more then the non firewire variant. Even if you don't need firewire, the improved cooling is worth it if the price difference is under $10. Untested at the moment, but should be no different (other then the extra features) compared to the above model.
Newest bios updates for this board can be found here.
Socket 1156 Boards:
These are BRAND new, so don't be surprised if there are weird bugs, particularly with early bios revisions. All of these boards are DDR3 only. With the memory controller now on the processor, performance should be virtually identical for any Socket 1156 board.
Gigabyte GA-P55M-UD2 Micro-atx format, cheap cost (by 1156 standards). Has 4 ram slots, 5 native sata ports (plus another 2 provided by a 3rd party controller), 10(!) rear usb ports, with 4 more usb ports on the motherboard itself. Other features are firewire, e-sata, gigabit ethernet and realtek HD audio. About the only apparent weakness of this board is no 1x pci-e slots, but there is 2 16x pci-e slots (with one being a 4x electrical), so this probably won't be much of an issue. This board is currently untested.
Newest bios updates for this board can be found here.
Gigabyte GA-P55-USB3 Atx format, moderate cost (by 1156 standards). Has 4 ram slots, 6 native sata ports (plus another 2 provided by a 3rd party controller), 10(!) rear usb ports, with 4 more usb ports on the motherboard itself, and 3 pci slots, 2 1x pci-e slot, and 2 16x (with one being 4x electrical) pci-e slots. Other features are usb 3.0 support, gigabit ethernet and realtek HD audio.
Newest bios updates for this board can be found here.
If you're not a performance user, or you are trying to keep your costs low, AMD is a better choice right now. Otherwise Intel is the way to go.
Regarding motherboards with integrated video, do NOT use motherboards with Intel integrated graphics (or at the very least, get a separate video card). Intel integrated graphics (and the drivers they use) are of such poor quality it will cause crashes with various programs, and actually slows the rest of the system down, even in normal every day tasks. Stick with either Nvidia or ATI integrated video (if you want integrated video), or use a Pci-E video card outright.
One final cost consideration: all things being equal, good quality motherboards for Intel cpu's tend to cost more ($30-$50 extra) compared to a similar board for an AMD cpu. Those trying to stay on a budget will want to keep that in mind.
Intel CPU recommendations
Totally avoid the Intel P4 (and Pentium D variant) cpu's, they are very old, run way too hot, and cost too much for the price/ performance level (a $50 AMD X2 will blow em out of the water and run much cooler to boot). The Celeron Conroe and Pentium E variants aren't horrible, but AMD cpu's at the same price point tend to perform a tad better, so for budget users you are much better off looking at AMD.
Be aware that the current LGA 775 and LGA 1156 heatsink mounts just BLOWS compared to the AMD AM2/AM3 type mount, and extreme caution should be used when working with it. Just adding or removing a heatsink off a LGA socket can damage the socket or heatsink mounts unless you are extremely careful.
Intel has 3 different platforms currently available.
Socket 775 with Core2 class processors - The current mainstream Intel platform. Its well proved, stable, but it's on the way out. Uses DDR2 or 3 ram depending on the board. For new systems, I'd skip socket 775 and move on to socket 1156.
Socket 1356 with I7 Cpu class processors - Extremely overpriced, but currently the highest performance option from Intel. Generally NOT worth the money now that the I5 is out. Uses DDR3 ram.
Socket 1156 with I5 or I3 Cpu class processors - This is the replacement platform for Socket 775. The I5 class cpus are faster then the Core series, and are only a little bit more spendy. Uses DDR3 ram. Avoid the hyper expensive models and stay under $300.
Socket 775 Boards:
The best choices in Core2 motherboards use an Intel chipset. Be advised that Intel in one of the most idiotic chipset / platform decisions in years (probably the worst since the early 8xx series fiascoes) decided to NOT include ANY native pata channels on their current ICH8 / ICH9 / ICH10 southbridges for the Core 2, forcing all the Intel chipset MB oem's to use 3rd party controllers (and these usually have lots of performance and compatibility issues) to provide this functionality. If you go with an Intel chipset, MAKE SURE to ONLY use sata hard drives and have at least one sata optical drive. If you have additional pata optical drives, its usually safe to stick them on the 3rd party controller. Usually this is only a problem for people trying to re-use old drives.
Avoid the Nvidia chipset boards, as the only advantage they offer over the Intel chipset boards is sli support, and sli generally is NOT worth it. Plus, the drivers for Nvidia boards tend be a lot rougher compared to Intel.
Make sure your board has official 1333 bus speed support (and not just the cheezy "OC" support). Almost all of the current Intel cpu's require this. Avoid older chipsets that don't support this (like any of the Intel chipsets prior to the P35/P45 series).
Gigabyte GA-EP45-UD3L Based on the Intel P45 chipset. Fairly cheap by Intel chipset standards. Features are fairly vanilla, 6 sata ports, lots of pci-e slots, and the IO plate offers an impressive 8 usb ports. Ethernet and audio are both realtek, so no wierd drivers to be concerned about there. The bios can be flashed right off a usb flash drive without needing to boot into dos (very handy!). Overclocking features appear to be very impressive as well. Stability is excellent, even while overclocked during heavy gaming or dvd encoding. This is my preferred board for Intel socket 775 cpu's.
Newest bios updates for this board can be found here.
Gigabyte GA-EP45-UD3R If you need firewire, this board is virtually identical to the above board, except it includes firewire and a extra 3rd party sata controller as well. The heatsink cooling is slightly improved as well. Usually runs about $10-15 more then the non firewire variant. Even if you don't need firewire, the improved cooling is worth it if the price difference is under $10. Untested at the moment, but should be no different (other then the extra features) compared to the above model.
Newest bios updates for this board can be found here.
Socket 1156 Boards:
These are BRAND new, so don't be surprised if there are weird bugs, particularly with early bios revisions. All of these boards are DDR3 only. With the memory controller now on the processor, performance should be virtually identical for any Socket 1156 board.
Gigabyte GA-P55M-UD2 Micro-atx format, cheap cost (by 1156 standards). Has 4 ram slots, 5 native sata ports (plus another 2 provided by a 3rd party controller), 10(!) rear usb ports, with 4 more usb ports on the motherboard itself. Other features are firewire, e-sata, gigabit ethernet and realtek HD audio. About the only apparent weakness of this board is no 1x pci-e slots, but there is 2 16x pci-e slots (with one being a 4x electrical), so this probably won't be much of an issue. This board is currently untested.
Newest bios updates for this board can be found here.
Gigabyte GA-P55-USB3 Atx format, moderate cost (by 1156 standards). Has 4 ram slots, 6 native sata ports (plus another 2 provided by a 3rd party controller), 10(!) rear usb ports, with 4 more usb ports on the motherboard itself, and 3 pci slots, 2 1x pci-e slot, and 2 16x (with one being 4x electrical) pci-e slots. Other features are usb 3.0 support, gigabit ethernet and realtek HD audio.
Newest bios updates for this board can be found here.
Amd CPU recommendations:
For budget machines, the AMD dual core cpu's are a great pick. When possible, get the lower wattage model cpu's if they don't cost a lot more compared to the higher watt ones. Rather then give direct links here, I am going to give a few suggestions, as pricing changes way too quick here to recommend certain model cpu's.
AMD currently has two socket types in production. Socket AM3 cpu's can use DDR3 or DDR2 ram, with the older Socket AM2 cpu's can only use DDR2. An AM3 class cpu can plug into either AM3 or AM2 boards, but AM2 cpu's only work with AM2 boards. So generally you'll want to buy an AM3 cpu, and an AM3 board if you want to run DDR3 ram, or an AM2 board if you want DDR2 ram.
With AMD cpu's, its generally not worth spending over $100, the Intel's is a better choice in the $100 and up range. Avoid the 125 (and above) watt cpu's at all cost, there are LOTS of reports of various motherboards dying when these are used, plus these models generate a LOT a heat. As a general rule, you want the 45nm models (or smaller), avoid the older 60 or 90nm ones.
Listing of dual core AMD cpu's
As always, do your homework and shopping, this isn't written in stone. Most of programs currently out do NOT take advantage of a quad core cpu, so don't buy one expecting it to magically double your performance. Unless an oem cpu is WAY cheaper compared to its retail brother, go with the retail cpu. 3 year warranty, and the retail heatsink/fans are pretty good quality. As a final note, you can stick an AM3 class processor in an AM2+ board as long as the board has proper bios support.
For budget machines, the AMD dual core cpu's are a great pick. When possible, get the lower wattage model cpu's if they don't cost a lot more compared to the higher watt ones. Rather then give direct links here, I am going to give a few suggestions, as pricing changes way too quick here to recommend certain model cpu's.
AMD currently has two socket types in production. Socket AM3 cpu's can use DDR3 or DDR2 ram, with the older Socket AM2 cpu's can only use DDR2. An AM3 class cpu can plug into either AM3 or AM2 boards, but AM2 cpu's only work with AM2 boards. So generally you'll want to buy an AM3 cpu, and an AM3 board if you want to run DDR3 ram, or an AM2 board if you want DDR2 ram.
With AMD cpu's, its generally not worth spending over $100, the Intel's is a better choice in the $100 and up range. Avoid the 125 (and above) watt cpu's at all cost, there are LOTS of reports of various motherboards dying when these are used, plus these models generate a LOT a heat. As a general rule, you want the 45nm models (or smaller), avoid the older 60 or 90nm ones.
Listing of dual core AMD cpu's
As always, do your homework and shopping, this isn't written in stone. Most of programs currently out do NOT take advantage of a quad core cpu, so don't buy one expecting it to magically double your performance. Unless an oem cpu is WAY cheaper compared to its retail brother, go with the retail cpu. 3 year warranty, and the retail heatsink/fans are pretty good quality. As a final note, you can stick an AM3 class processor in an AM2+ board as long as the board has proper bios support.