The ATI 3850 and 3870 are reasonably good cards (according to reviews) with significantly lower power requirements than the 2900. The 3870 benchmarks a tad below the Nvidia 8800GT, which is the performance for price leader at the moment, being much cheaper than the 8800GTS yet essentially as fast.
However, that is for reviewers. Although all three have launched, only a few have hit the market and places like newegg.com don't have any of the three in stock. Also, they benchmark so well, and have been described as such a good deal in the reviews, that the asking prices are above the announced "projected" street prices.