I think to get the most out of LBP (and note that I personally have not done this), you need to get into the level builder. People have done some crazy stuff; even more so with LBP2. Even if you don't want to make anything, there's tons of fun stuff for download if you can separate the chicken salad from the chicken shit.
Got my free games: LBP and inFamous on PS3, and LBP and ModNation Racers on PSP. Haven't really played any of them yet.
North America * Hell's Kitchen * Lock's Quest * Mazes of Fate DS * Mystery Case Files: MillionHeir * The Price is Right * Spore Creatures * Viva Pinata: Pocket Paradise Europe * Bakushow * Dragon Quest: