Which one is better for gaming?

HP Pavilion p6110uk Desktop PC

Genuine Windows Vista Home Premium 64-bit
AMD Phenom X4 9650
4 GB DDR2-SDRAM
640GB SATA Hard Disk Drive
ATI Radeon HD 4350

or

Dell xps 420

windows home premium 32 bit o/s

Intel quadcore 6600 2.4ghz

3gb ram

750gb h/d

8800gt gfx card

thanx in advance.

dell xps !

if i had to choose id still pick the self built machine on my blog. 350 bucks CDN gets you a nice median between those two machines with no OS or periphreals (monitor keys mouse, speakers)