I am gaming mostly from the sofa on an HD7850 propped up by an ageing Core2 processor.
Full-blown 1080p is fine for almost everything. Sometimes I have to disable AA to stay at 60fps for stutter-free vsync but that's just me being picky I think.
I have also had the chance to test a 650Ti which feels remarkably close to the HD7850 at 1920 x 1080 given its price. Whilst you normally see HD7850's at $175 with $20 rebates and some free games, you can usually find a 650Ti down to $120.
It's priced closer to an HD7770 and whilst you don't get free games with it, it is much smaller which is good if you don't have a lot of space in your PC (My cramped HTPC was the reason I borrowed one from work. It's amazing what you can shoehorn into a case when you use enough cable ties though!)
This is my signature. There are many like it, but this one is mine. However, my signature is neither my best friend, nor is it my life. I also have no desire to master it and my worth is not signature-dependent.