All of the Rayman games on PS2, along with the 10th Anniversary Rerelease collection of the games.
Rayman Revolution is a reimagining/remaster of Rayman 2. Instead of a level select-like hub to traverse through, you instead have an open area that links all of the stages together, making the world feel more complete.
Rayman M is a multiplayer based Rayman game. If any of you have seen Rayman Rush on PS1, its basically that but theres arenas as well as races.
Rayman 3 is... Well Rayman 3. It's a really solid game that holds up even to this day, as well as being really funny.