RPG reigns supreme for me followed by TBS, RTS, open world sandbox, music based, and then shooters.
Examples are Skyrim (RPG), Chrono Trigger (TBS), Star Craft (RTS), any GTA ever (open world sandbox), Rockband (obvious), and Battlefield 2: Bad Company (shooter).
It gets even better if some of them get mixed, as they often do, and make interesting combinations of genres.