Just curious, why do you want to avoid ATI products? Are you looking to go SLI? In that price bracket, after eliminating all ATI choices then the definite choice in my opinion is the GeForce 9800GTX. You should be able to find that for $200 or less now. And the 9800GTX+ should be available soon for about $20 more. I would recommend EVGA for any GeForce cards. But other well respected brands are BFG and XFX.
If you were to consider ATI cards then the HD4850 would be the obvious choice. In most benchmarks and reviews I have seen it beats the 9800GTX. There is a thread
here that I started and people posted their opinions about which brand to choose. That is also going for about $200.