endeavour37a :
Not even a question, 770 of course.
i'd say it's a question...
First of all the 7970 can overclock like a beast. It's doubtful either card is faster then the other when both are fully overclocked. Second the 7970 comes with 4 games... if the op wants those games i'd say it's one heck of a value. Throw in the fact the 7970 is a great bitcoin miner...
that said, if the op wants to get multiple gpus down the road he's better off with the 770. if he doesn't want to overclock, the 770 is a little bit faster. If he's concerned with noise and temps, the 770 is a better buy. If he has no interest in the games the 770 is a better buy.
i wouldn't call it a no brainer. it's pretty much dependent on the OP's needs.