" As for AMD you might have to be more careful"????
Do not bother with the above comment. Both AMD and Nvidia make some good cards and some bad cards. Cards failing and service is more to do with the end distributor then then parent company itself.
You can have a look at this for more info, decide on a budget and pick up a card accordingly.http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107.html
Also, the screen resolution matters. I am rocking a 7870 on a 1920x1080 screen and have never seen any slowness what so ever. My older AMD Athlon rig has a 5670 which pushes a 1440x900 and it worked fine albeit on lower settings. My 8600 GT rocked prior to that and I have never seen any of my cards failing.
So it depends on your budget. Throw us a budget and I can get back to you with a recommendation.