I'm playing Katamari Damacy and X-Men Legends both for PS2.

Katamari Damacy is a crazy japanese game where you roll up a sticky ball of everything to a specified size within a timelimit. Lots of fun and a great sense of scale and style. It's great starting out being able to roll over thumbtacks, then eventually getting big enough to roll over people. They make great screams :D

X-Men Legends is a cool action/RPG game featuring the X-men characters. Kind of like a Diablo 2 type game, but you have a team of 4 most of the time, and can switch on the fly between which you control, the computer taking control of the others. I don't have any friends, but I guess it also allows other players to jump in whenever and control someone else from the team. So far, it's been great fun blasting through levels and beating up sentinels. Wolverine has been my character of choice so far, but I just rescued Gambit and hope to start using him more often.