until I fitted my gtx470 my Antec P180B was very quiet with a 8800GTX, the P18X's are quite good.
Using a mini p180 here,
along with some relatively warm hardware, and this thing can be made almost whisper silent...
Most of the time the only way to tell whether my computer is on is by looking at the little LED
My reccomendation goes to the Antec P180 Series