The only reason I upgraded from on-board graphics was because I wanted to run dual displays, so the idea of spending $899.99 on a high-end card makes my stomach do a backflip of disbelief. Still, people laughed at me when I spent thousands on Michael Jackson's first nose, but I still think it's the best investment I ever made. Anyway, your nine-hundred bucks gets you EVGA's 8800 Ultra Black Pearl edition, a stonking water-cooled PCI-E card with a core speed of 655MHz and 768MB of DDR3 memory.
Big money should get you big figures, and the Black Pearl doesn't disappoint. Analogue output is 2048 x 1536 while digital hits 2560 x 1600, and in testing a pair of the cards managed a 3DMark06 score of 25,000. It's a hungry beast, though, requiring two molex hook-ups and obviously you'll have to have a water-cooling system to take advantage of it. EVGA claim the Black Pearl runs 30 degrees centigrade cooler than the standard 8800.
It's on backorder at the moment, which gives you a little time to save up.