Best Same-Device iPad Multiplayer Games?

My GF and I have a lot of fun playing Bejeweled together on her Air. I'm wondering if there are other noteworthy games worth checking out? Competitive is okay, but it stresses her out sometimes, so cooperative ones would be ideal.

shes currently enjoying Juice Cubes, but dunno for how long considering there's probably a pay wall soon. So I guess Puzzle games would be the first choice. She's definitely not into action games and other stuff dudes play. She already has Letterpress, but I think she's over it.

price isn't an issue so paid apps are okay. IAP games are okay if it's reasonable and doesn't abuse the system.