The Tech Report published a review of eight power supplies, they took a look at 700W to 1000W models from Antec, Corsair, Gigabyte, Hiper, PC Power & Cooling, Super Talent, Tagan and Ultra.
As you can see, we have units between 700 and 1000 watts. This is certainly pushing the upper range of what's necessary for most PCs, but it's easy to build a high-end system that demands this much juice. Even as processors display admirable restraint in their power consumption, each new crop of graphics chips seems to be more power-hungry than the last. With both AMD and Nvidia expanding their respective CrossFire and SLI multi-GPU schemes with additional cards, there's certainly a place in the market for high-wattage PSUs.
Of the units we've assembled today, Antec's TruePower Quattro has the highest output rating, nailing the kilowatt mark. Behind it, we have four units spanning 800-880W and three bridging the gap between 700 and 750W. Our test suite is designed to be largely independent of wattage, so PSUs with lower output ratings won't be unfairly penalized when compared with beefier competitors.
Check it out over here. The reviewer says the Antec TruePower Quattro 1000W is the best choice, it has good all-round performance and is priced at around $186. The Hiper Type R Mk II 880W costs a bit more but receives the Recommended award for its high efficiency and low noise levels. The only PSU that isn't worthy of your hard earned dollars appears to be the Ultra X2 750W, it's the cheapest of the pack but its performance wasn't stellar.