780 is the best out of all of them with the highest price. Under it the 770 being the improved SC 680, 7970 including 4 free games, crysis 3, bioshock, tomb raider, fc3 blookdragon and being priced at a decent amount. 760 running last and priced at the lowest.
If you want something in the middle get 7970 with all the free games if you just want bang for the buck.