When I built the last machine, it was purely to get back into PC gaming, my computer before it died. So, here is the previous build:
Motherboard:
http://www.tigerdirect.com/applicati...?EdpNo=3975887
CPU:
http://www.tigerdirect.com/applicati...?EdpNo=3740794
CPU Cooler, I went with stock for about a year, then I got into overclocking, so I needed more "oomph" with cooling:
http://www.newegg.com/Product/Produc...82E16835118074
RAM:
http://www.tigerdirect.com/applicati...?EdpNo=2937546
Vid card:
http://www.tigerdirect.com/applicati...?EdpNo=6075290
System Hard drive:
Some 5400 RPM 80 GB HD I got from my college, we used to use them for labs, but they started handing out portable USB drives, so the hard drive was mine to use as I wanted.
Power Supply:
http://www.tigerdirect.com/applicati...?EdpNo=4256917
Case:
http://www.tigerdirect.com/applicati...?EdpNo=3911521
Monitor:
http://www.tigerdirect.com/applicati...?EdpNo=4942567
Just within the past month, I built a whole new system, designed for the FX processor when they work out the lack of power issues and get the Bulldozer a little more on track with Intel's CPU's, and to check out the Scorpius platform when I do upgrade the CPU again:
Motherboard:
http://www.newegg.com/Product/Produc...82E16813131735
CPU:
http://www.newegg.com/Product/Produc...82E16819103913
CPU Cooler (cheaper on Tiger Direct for some reason):
http://www.tigerdirect.com/applicati...p?EdpNo=581556
RAM:
http://www.newegg.com/Product/Produc...82E16820145313
Vid Card:
http://www.newegg.com/Product/Produc...82E16814125371
Main Storage Drive (which is what my OS is installed to, along with WoW, BF3, and Starcraft 2):
http://www.newegg.com/Product/Produc...82E16820233220
Same power supply, no need to replace that, same with monitor.
Case:
http://www.newegg.com/Product/Produc...82E16811119225
Notes:
Keyboard is the original Logitech G15, I have a G500 mouse for non-MMO games, and the Cataclysm edition WoW mouse for WoW & other MMO's. I also use the Belkin Nostromo n52te (before Razer took over) for all games except SC2.
I have a 1 TB HD for holding fraps footage, and a 500 GB drive for media and other stuff.
The main reason I upgraded was for streaming. Before, I could stream raids and pvp at 720p and it would be decently smooth, but it would be fuzzy due to my system's limitations. Now, with this build I am streaming raids and pvp at 1080p, and it's almost crystal clear. The only thing holding my stream back now is my internet.
Other games are much smoother as well, Battlefield 3 on a 64 person server is smooth as hell. I will be getting a second video card (same one) for Crossfire in January.