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.
I haven't played regularly since February. I logged on a few times to maintain a guild bank for a guild I had. My sub ended in October and I won't renew. I don't see anything about the expansion to change my mind.