Mostly GTA V, because I removed my storyline save mode recently and had to restart. It was kind of a good thing, but still frustrating. I'm now at a higher percentage of completion than my old file was. And I only have 1 spaceship part to find. Not sure where I missed that.
Aside from that, played the Destiny and am now salivating over the idea of the actual release, finished the first Borderlands because I started it at a friend's house but never got it finished and I wanted to before I jumped into 2 for any real playthroughs (I've run around and killed shit with my son, but not actually followed the story much), went back to RE5 to see if I could get those last pesky few achievements and then realized that I never downloaded the VERSUS DLC and don't have any interest in it, so I can't get all of them anyway. Played Motocross Madness because it was the free with gold download on 360 and it was kind of fun, if for no other reason than it actually uses my 360 avatar, and he looks like Deathstroke, so Deathstroke riding motorcycles... fun. Skyrim on and off, downloaded the ridiculous patch for Defiance, tried to get into the game, and just can't. It drives me a little batshit that I've spent more time installing and reinstalling than I have playing.
Felix, I've not tried the ME3 multiplayer. Is it worth stepping into? I've always been curious, but never played it.