Dead Rising is one of my new IP favorites for this generation, and the sequel did everything right, including the what-if Off the Record version. Its a game series that can be as serious or silly as you want to take it, as focused or distracting as you want to play it, and as shallow or as rewarding as you want to experiment and explore in it. Its such a refreshing and fun take on the wave of otherwise generic and forgettable zombie games.
Also, its better with multiplayer, but make sure you two are on the same page. If one person is trying to run missions and the other just wants to mess around, you're going to frustrate each other.