Why's that?
They're designed to do server stuff, not gaming.
Anway an awesome high-end system would be(if that's what he's looking for):
Thermaltake Armor Full Tower
Q6600
ASUS P5N32-E SLI
2GB G.Skill DDR2-800 HZs
EVGA 8800GTX
Corsair 620HX
WD Raptor 150gb
Seagate 7200.10 320gb
Sony NEC Optiarc DVD burner
Samsung 226BW 22" monitor
Logitech G15 keyboard
Logitech MX518 mouse
X-Fi XtremeGamer sound card
Logitech Z-5500s sound system
Thermalright Ultra 120 Extreme w/fan
Comes to about $3k