What are the best freeroam/sandbox games for the xbox 360?

Ive played grand theft auto 4 and red dead redemption and i only care for the free roam and multiplayer like getting rocket launchers and flying a helicopter on a rooftop shooting at citizens and police below or ganging up with friends and go hunting or have shootouts.ive played just cause 2 demo and liked it but it dont got splitscreen or even online and people say once the story is over the game is boring.crackdown looks stupid and horrible graphics. fallout and oblivion are stupid. assassins creed aint sandbox to me. no mafia, saints row or the godfather either. i prefer a game with splitscreen and multiplayer and a wide variety of vehicles and weapons (red dead redemption is an exception