Resident Evil as a main series I dip into a lot. The Dead Space remake was amazing. I really like Mass Effect but I've played it so many times now that I just can't pick it up anymore. I really miss the romance sides of it and the mechanic of being able to pass choices over from game to game.
I really love puzzle platformers with meaning like Brothers a Tale of Two Sons. But anything that pushes the medium is amazing. I wish AAA titles would push the boundaries more often and get out of the gamified movie loop