Hmmm. LSL5, 6 and 7 are - well, yes, a little episodic and not very character-building, but still fun.
My favourite? I haven't played LSL in ages, but I think LSL2 is my favourite. Poor Larry... everyone picking on him because he's bald. Aww.
Also, the communist sub-plot is ridiculously funny. (Love the James Bond moments!)
LSL3 is my second favourite... again, because of the split between Larry/Patty and everything wraps up really nicely in the end. Still, a couple of things I didn't really like - the bamboo maze (argh!!) and the water-ride on the log (double argh!!)
It took me FOREVER to get through that water-ride thing. Why in the name of sanity it was put in, I have no idea. /rant