Ok here we go, I built this recently:

Computer: Core 2 Duo E6600 2.4Ghz overclocked to 3.2Ghz (400x8)
Motherboard: Gigabyte 965P-Ds3
RAM: 2048Mb DDR2 667Mhz overclocked to 800Mhz 4-4-4-x
Graphics Card: x1900xt overclocked to 675/765
Sound Card: Creative Audigy 2 ZS
Hard Drive: 250Gb SATA II 16Mb
OS: Windows XP Pro SP2

Using this on a 19'' LCD, optical mouse/keyboard, along with 5.1 speakers

Everything in total (not including the monitor, keyboard, and mouse) ended up costing me $1500, that includes the case, cooling, powersupply, extra cables, speakers, and etc. So I think I did pretty good.