I just ditched my liquid cooling system and went air cooled again. I have a lian li aluminum chassis with 4 120 mm vantec stealth fans(my personal favorite for the level of quiet the provide).

The guts are outdated Asus mobo core 2 duo, nvidia 9800GT, 360gb SATA 2 RAID 0 and 4 gb Corsair DDR 667.

I run vista ultimate with all the bells and whistles as well as a local sql server instance, IIS, and a visual studio 2005 with infragistics, and 10 or 15 various debugging programs without a hiccup.