Hi all. I think it is finally time to get rid of my EVGA 260GTX. It has served me very well till now. I am having a hard time getting acceptable frame-rate performance in a few new games. And I can't even get any AA on with decent FPS

So I am in the market for a new GPU.
I know it should be a no brainer But there are a few parameters. And since I now have three kids my time to search and read every gpu article out there just isn't feasible.
So I have come here once again for the best advice you can get on GPU's among other computer parts. I only have around 200 Canadian to spend and that is including taxes. I don't mind Nvidia or ATI. I have had more Nvidia GPU's because of the Physx support. But I will consider a ATI GPU this time. I really like the EVGA Step-up program though.
Please help guys. Also keep in mind that I am running a 24inch LCD at 1920*1200 Res and I mostly game on my Rig. So video editing or Blue ray playback or 6 screen support does not matter.
Cheers