To be honest, I run SLI 8800GT, a 3.0GHz Q6600, SB Xfi fatality with front IO bay, 2 HDD's, and 2 Optical drives on an Antec True Power Trio 550W with a combined 12v of 41 amps on the three 12v rails. I would have bout a Corsair 620W or the Antec TP3 650W, but I already owned this one, decided to try it, and it's been stable as a rock.
Not a great price(seen the 650W for this price), but that's my PSU:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371002&nm_mc=OTC-Froogle&cm_mmc=OTC-Froogle-_-Power+Supplies-_-Antec-_-17371002