I already got Little Big Planet as a multiplayer title, but some days I might not feel like being adventurous. So here are my options:

-Uncharted 2: Among Thieves (seems to be virtual PS3 perfection with great multiplayer)

-Demon's Souls (hardcore RPG with some MP options)

-Borderlands (shooter RPG that's highly anticipated and promises 4 player co-op multiplayer)

Just because I got Borderlands coming in the mail, but I might opt to get it swapped out for Uncharted 2 and purchase its predecessor for the same of story or Demon's Souls.