[quote name='SeanAmI']It doesn't have to be Nvidia if there is a better Radeon[/QUOTE]
If you go with radeon then visiontek is the company I cant reccomend them enough.
When I buy a new video card Im not a fanboy, Ive owned nvidia and ati stuff just when I get a new card I go with who is the best at the same. Im running a radeon now and have for awhile been using the same card.
Bottom line is whatever you get is going to be better than what you had before, use less power and output less heat. So radeon or nvidia, either way youll have a better card.
I suggested those nvidia cards purely because its what you have already which will make upgrading easier since you wont have to scour your pc ridding it up nvidia registry entrys and drivers to ensure you dont have a problem when using a ati based card. Its not real common but unless you get rid of them all it can cause minor gaming problems if you have leftover drivers when switching brands.