I built my own. I have built all my own PC's since I was about 15. Screw prebuilt. My parents gave me the cash for my current rig when I graduated from college. I don't remember the exact figure but it was a lot. I use it for gaming, general PC work, Photoshop work, and 3D modeling with Maya/ZBrush.
Case: NZXT LEXA BlackLine with Red LEDs
OS: Windows XP x64
Motherboard: ASUS M2N-E
CPU: AMD Athlon 64 X2 6400+ Windsor 3.2GHz Black Edition
Fan/Heat Sink: Zalman 110 MM Solid Copper CNPS7000C-Cu with Blue LED
RAM: 8 GB Patriot Extreme Performance DDR2 800 (PC2 6400)
HD(3): 1(Boot Drive): 150GB Western Digital SATA Raptor X 10000 RPM, 2: 320GB Seagate SATA Barracuda 7200 RPM, 3: 1TB Seagate SATA Barracuda 7200 RPM
Video Card: NVIDIA Quadro FX 4600(768MB GDDR3 RAM)
Sound Card: Creative Sound Blaster X-Fi XtremeGamer 7.1
Monitor(2) - 1: ASUS PG221 22" 2ms Widescreen LCD, 2: View Sonic 19" CRT(yuck)
Mouse: Logitech G5 7 Wired Laser 2000 dpi
Keyboard: Logitech Pro 2000