usually, when I go to a sleepover, we mess around with lego 'till adults tell us it's about time we went to sleep (usually very late indeed), at which point we go to bed and read, draw, or play a game which involves inventing strange things-the object of the game being to burst out laughing.
I'm kinda neutral on this subject. I guess I've never been to a really good sleepover, but then I guess most guys don't do that sort of thing.