Which video card would you recommend for my set up?

Hi, My current setup is Sabertooth x58, i7-950, 12gb corsair ddr3. Power supply is 550w. I currently have an nvidia 9800 GTX but the vRam is starting to fail, so I'm lookin for a new card. Preferably one that is top of the line and will stay one of the best for the next couple years. Any good deals right now? Thanks!