The more I read, the more I'm getting confused if 8000 or 9000 series are better.  It seems there are a lot of factors that affect which is better so I'll just post my specs and see what you guru's think will be best for me.
 
I game on my main at 1600x1200 and have a second monitor I use for ventrilo, internet browser, etc... at 1024x768.  My mobo only has one PCI-E 16x slot, so I'd like a card that can perform at or near SLI capability.  I'm looking at spending around $300 but can go a little higher.  Oh, and I run XP Home incase that makes a difference.
 
Thanks!

8800GTS 512 (also consider the 8800GTX too since it has got a nice proce drop)
 
Dont get the 9800GTX because the old 8800GTX beats the 9800GTX in some cases and also the difference between 9800GTX and 8800GTS isnt much (noticeable) either so your bets buy would be withe 8800GTS 512 or 8800GTX