I would recommend the LG G2, due to the 2 gigs of ram, screen resolution, Quad-core 2.26 GHz Krait 400. Since you'll be running emulators and games like GTA, you'll eventually get tired of using touch controls and want to move on to a controller. Then you'll end up realizing that, unless you want to shell out 80 bucks, your only other option is to buy a ps3 controller and using that. However, to do so, your phone must be rooted. But fear not, the LG G2 is super easy to root. Took me less than 2 minutes (And it was my first rooting)
TL;DR: LG G2 is the best choice IMO.