Newegg.com and build it yourself is always my first recommendation. So you know my credentials (so you aren't listening to random people as Hammy says) I've been building computers for clients for 8 years now and this year alone I've built seven....even in the bad economy.
Best bet right now is to wait until the DX11 cards come out. I always,
always recommend AMD/ATi to people who buy computers....Intel and Nvidia are overpriced for very little gaming gain. Right now, and for the foreseeable future, your best bang for buck will end up being AMD/ATi. They also have the best integrated NB/SB right now...the SB850 is sheer awesome.
As for your other components, recommendations:
Motherboard: Asus, MSI or Gigabyte
RAM: Corsair or Kingston
Power Supply: Corsair or Enermax
Case: personal preference, but I like Antec
Hard Drive: Western Digital (accept no alternatives! WD is the only HDD company in -eight years- that has never had a failed hard drive on me...seagate has had nineteen, samsung twelve)
DVD-Drive: grab whatever is cheap...you can get a nice sony SATA one for 40 bucks, works like a charm
Monitor: another personal choice, I like ViewSonic but they tend to be pricey. Shop around some.
Sound Card: Asus makes a nice alternatice to the Soundblaster series, but darned if I can remember it off the top of my head. My Bose speakers have their own sound driver so I don't use sound cards.
There ya have it, hope it helps
