I'm in the process of parting together a PC and have been looking at PSU's for the last two weeks waiting for a deal on a name-brand 750w+ PSU and just came accross http://www.newegg.com/Product/Product.aspx?Item=N82E16817371009. It seems like a steal at $120.11 shipped with tax, the $20 'code' (which actually shows -$28.00 in the cart) and free shipping. Not to mention it is modular.
Originally I was looking at http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006 which is $99.99 after everything currently, but I would have to go through the hassle of the mail in rebate. Also, it is 750w instead of 850w and is not modular. The best thing about this PSU seems the single +12v rail which is nice, but the Antec is bronze 80+ certified while this corsair just has the standard cert.
Wattage isn't nearly as important as stability on the 12v rails. I recommend Corsair for reliability and stability. A lower wattage corsair PSU will out perform most other higher wattage PSU's hands down.
I have seen a Corsair HX520w power a rig with Q6600, 2 HD's, 2 DVD, 8800GTSx2, etc..with no sign of wavering on the 12v rails.
Right now I have a Corsair HX620w, Corsair HX520wx2 and an OCZ Stealthstream 600 and all are excellent PSU's.
In my opinion, there are very few systems that require a 750w+ PSU. High wattage does NOT always equal high-end.
Buy.com is has been runn the Corsair 750 ps at around $100.00 or so after rebate. I picked one up for my new rig shuld be plenty of head room for my raid and quad core( NewEgg had a heck of a deal on Seagate drives a few days ago so the new rig gets a nice fat raid, more room for video editing!) From what I have read the Corsair PS are top quality!