I feel your pain bro... but I've always stuck with ATI.  ATI isn't without problems but I have yet to run into a problem that I'm 100% certain switching to Nvidia would eliminate.

That said... some games work better with one or the other.  The whole power requirements thing on these cards has become a real pain in the butt.  You can't go by a PSU's overall output rating anymore.  My advice is to find out how many amps the video card wants and then pick a PSU that has MORE than that amount of amps on the 12 volt rail... no matter how much it costs.  You don't need a dual or multi rail PSU and I've seen valid arguments for sticking with a traditional single 12v rail PSU.

Right now I really like Corsair's power supplies.  There's another company called PC Power &amp; Cooling and their PSUs always get extremely good reviews but they're also not cheap.

Ultra PSUs = major crap and avoid them at all costs!  I have one that was fine for 1 year.  It still runs everything fine in 2D windows desktop mode but I'm very certain that it's output capacity degraded over time and it is the cause of all the problems I've had with UT3 crashing, UT3 artifacts and my monitor just plain going blank or losing the signal in the middle of a game.  Neither my GPU nor CPU ever gets too hot in my system to trigger any kind of hardware shutdown yet the warmer it is the more likely it is that I'll have problems with UT3... or problems with my Ultra PSU's output wattage.

One more thing in case you don't know.  When you see a 12v rail that is rated for 30 amps you can find the wattage by multiplying the volts and amps.  12 x 30 = 360 watts.  You can have a 1000 watt PSU and STILL have a 12 volt rail (which powers both your CPU and video cards) that doesn't have enough amps to run everything properly.

http://www.pcpower.com/technology/myths/#m8 - that page may be biased because they make and sell PSUs but it's the only page I can think of off hand that has a good reason for why a single rail PSU is better than a multi rail PSU.

Finally... another thing I've been through in the past is Via chipsets.  I'll avoid them at all costs after my experiences with my Asus A7V333+Raid motherboard!  I usually found a way to make everything work but it was a real pain in the butt sometimes.  There was one solution for my chipset on that motherboard that came from some random person on the internet that made his own drivers for the Via chipset and then shared with the world.  They weren't easy to find either.

Wish you luck man  :D