In terms of performance, the GTX560ti is stronger than the rest.
You might review this graphics card heirarchy chart:http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107-7.html
But realize that the graphics market is very competitive, and better price performer cards are continuously being launched.
In a sense, all the cards you listed are outdated except the 7770 which is the weakest, and the only one to use current 28nm technology.
My advice... Buy the strongest graphics card you feel comfortable paying for today.
When it no longer does the job, sell it and replace it with the next best thing.