Depends on how many people you want to play with. For two I found games like army of two to be super fun. With more people I've never gone wrong with old classics like smash bros or guitar hero/rockband. In fact smash bros and guitar hero/rockband are some of the only games I still regularly enjoy with friend years later without having gotten any new consoles or games. They're the kind of game that you never really finish and can keep coming back to.
What genre of games were you looking to play specifically?