It's all about preferences,cards you had in the past, if you prefer nvidia or amd, independent of the performance of the cards in question.
Also if caring about value $/performance the 670 like Derza10 said, might be your best choice like a 670 msi pe(since you had a 680 lightning in the choice).
The 670 gtx will deliver a good gaming experience at 1080p.
In not caring about that, the 7970 ghz beats in most games in the benchmarks, the 680 lightning overclocks really well, you can't go wrong with any of those.