I have a Geforce 7950 GX2 and for all my gaming needs this card delivers 
Also used to be a Huge ATI fan, but a lot of newer games were developed with Nvidia support build in hence my switch. ATI however might be again a future card since their pairing with AMD if your an AMD fan aswell
In your upgrade priorities I would put the Ram down first... For the bigger Graphics card you are gona need more system resources... And though Ram is not always noted as a huge improvement you will feel the lack if you dont have it. Secondly your PSU to get your system ready to handle the new Graphics card then the Graphics card
When you are ready for graphics upgrade you can think of PSIe and double and quad card configurations
BTW any one tried 2 x Geforce 7950 GX2 in Quad mode yet?
Also used to be a Huge ATI fan, but a lot of newer games were developed with Nvidia support build in hence my switch. ATI however might be again a future card since their pairing with AMD if your an AMD fan aswell
In your upgrade priorities I would put the Ram down first... For the bigger Graphics card you are gona need more system resources... And though Ram is not always noted as a huge improvement you will feel the lack if you dont have it. Secondly your PSU to get your system ready to handle the new Graphics card then the Graphics card
When you are ready for graphics upgrade you can think of PSIe and double and quad card configurations
BTW any one tried 2 x Geforce 7950 GX2 in Quad mode yet?