I am planning to buy either gt 430, gt 520, gt 220, or radeon hd4850. Which cards are the best for the said games? Thanks.
See my ATI 4650 2 GB Plays the game at fullspeed. So you can get any of them. I would go wth ATI.
If you like Nvidia other fancy things then you have your own choice.
I'd almost always suggest NVIDIA. Except in your case your options are pretty bad, because I'd never suggest a NVIDIA card lesser spec than 560. In this case I believe the AMD will be better. It will easily out perform the three NVIDIA cards you've posted.
Nvidia is better but AMD is not bad. It has a higher clockrate and is much stable at higher clockrates too. while some nvisdia cards blow up when overclocking.