A radeon 9800pro...should fall neatly into your budget:
Methinks a great buy for 250 bucks.
Too lazy to find better info.
EDIT: or what Satis said..they're both great cards who're virtually head to head judging by Tom's hardware benchmarks, but if his card is way cheaper than well...
*edit from satis* fixed your long-ass, format-breaking links. Please stop breaking it. I'm tempted to start deleting your posts instead of fixing them.