I've decided to build a computer rather than buy one from Alienware. It seems like I'll get more for my money if I just build it rather than buy one pre-made. Also, I know there's a bajillion other threads with answers for exactly what I'm asking, but I'm too lazy to sift through them all to come to a good conclusion.

My budget is around $1000 to $1500 and I think I can get something pretty good with that.

I'm thinking an Intel Quad Core Q6600, 700 watts for a power supply*, Dual 512 NVIDIA GeForce 8800 GT with SLI, 2 GB of RAM memory*, and 300 GB of HD memory*.

I don't know what kind of sound card I want, but I want something pretty good. I'm also not sure what motherboard I want or need. Also, XP > Vista Home Premium? * means dunno which brand.

Hehe, I'm not sure this might fit my budget. :P

This is what I got so far:
Computer Case - RAIDMAX Sagitta 2 Mid Tower - $40
HDD - Seagate Barracuda 500GB 7200 RPM - $100
Memory - G.SKILL 4GB (2 x 2G SDRAM DDR2 - $100
Power Supply - COOLER MASTER Real Power Pro 750W - $100
Processor - Intel Core 2 Quad Q6600 2.4GHz Quad-Core - $240
Sound Card - Creative 7.1 Channels Sound Blaster X-Fi XtremeGamer Proffesional - $85