Looking to purchase new Graphics Card.

I'm looking to purchase a new graphics card, now I have a really nice graphics card right now, but I'm just looking to have my computer run even better yet. I have a Dell Xps 8300, if that helps any, but I don't know the specs of the Graphics card. Now, I record videos, and I want to have them as high of quality as possible. I record with FRAPS, so I'm good with what I record with, but I want to have the highest/higher settings in my game, without worrying about performance. I'm not looking at spending an astronomical amount on the Graphics card, but I am looking at 300-500 dollars for one, I just want to know what Graphics card would give me the best bang for my buck in that price range.

Thanks in advance,
sportsnut198