Upgrading computer

[NosBoost300]

Okay so at the moment i have a a pretty good computer, but i have too much cash on hands atm and would like to spend em. What would be a good step / good steps from the computer i have atm? Specs =

Asus p5k (bearlake p35)
QuadCore Intel Core 2 Quad Q6600 (clocked to 3ghz)
Gainward 8800gt 512mb b
2x 2 GB DDR2-800 DDR2 SDRAM (A-Data)
NVIDIA GeForce 8800 GT (512 MB)
Creative Audigy 2 ZS (SB0350) Sound Card(don't need a better one, using mainly headphones)
SAMSUNG HD501LJ ATA Device (500 GB, 7200 RPM, SATA-II)

Samsung SyncMaster 930B (Digital) [19" LCD]

right there.. that just plain don't make sense.. p35 only has 1 pci-e slot

 

[philbar71]

mabye he only has one and just made a mistake or he has 2 and only uses 1

 

[Wetop]

Hmm yes i made a mistake, has 1 only, sorry about that. Dunno where that first one came from...