Little Big Planet, millions of user created content, a lot of it is decent, they have DLC like The Muppets, Toy Story, Metal Gear Solid and Pirates of the Carribean, that is end less amount of fun.
Yes, and the key word in your phrase is user-created. While Harmonix has a UGC initiative available in the form of the RBN, when was the last time you saw a developer continuing to support a program with weekly DLC for as long as Harmonix has? Because, as you point out, LBP's content isn't created by Media Molecule, but rather the users.
DLC on DLCQuickPlay.com. Gamertag is the same as my Forum name. Hit me up if you wanna play!