I would recommend the MSI HAWK GTX460, a great solid card, for me it has exceeded expectation, Will def play wow maxxed out on the highest of resolutions, but it will also give you some room in case you want to play crysis or any other fps.
Price to performance, you really can't beat a 1GB GTX460, the prices continue to drop, I've seen them on sale for as low as $139 locally. This is a solid recommendation.
I recently purchased an HD6950 and would also highly recommend it. 1GB versions are available for ~$240, usually with mail in rebates as well. If you can afford to go in the $250 range, you won't find another $250 card that performs better than the 6950. If you're trying to stay in the $150-$200 range, the GTX460 is still a solid performer. I also like the 6950 because it has good overclocking headroom. I bought an MSI and can easily overclock the GPU and VRAM up 10% without any voltage adjustments - runs great!
I also play WoW, so in refernce to that: I was recently using the GTX460 768MB version and was able to play WoW with good FPS on moderately high settings (slightly above mid-level settings), running 35-70 FPS in normally populated areas. With the 6950, I have everything on Ultra and 8xAA, 16xAF, I'm getting 35-85 FPS, but again, that's with all settings on Ultra with AA and AF maxed - both cards, I was running at 1920x1080.
WoW can also drag on your CPU in heavily populated areas, large raids (where there's lots of particle effects), etc. Hope this helps!
Edit: Just to note, I'm referring to average FPS, not peak. Don't let people fool you - yes, some lower end cards can handle WoW with very high settings, but the only times they get high FPS is when they're in a 5-man or standing in a corner. If you want the game to run smoothly all the time and still have high graphic settings, I stand by my recommendations. Just as a side note - my 6950 hits 140FPS+ in 5-mans and standing in corners, lol.