Here is some info from one of my previous posts:
SpeedyBiker (local multiplayer, but I could not verify whether it is live, or if it just saves the friends record and displays it as a shadow)
Risk (local multiplayer)
Monopoly (local multiplayer)
Fruit Ninja (this does not have a local multiplayer, so you would have to connect via GameCenter and select to play against friends)
Wesnoth (online multiplayer. Should be fine if one of you creates a map and the other one joins. It's more of a strategy game. Definitely worth checking it out)