I like Legos but strangely enough I have never really owned too many. The only Lego set I had was one of those Lego Mindstorms kits. I think those are really cool.
Growing up I had a friend who had tons of Legos. We spent an entire day once building huge forts and weapons for our Battle Beasts figures out of Legos and staging elaborate wars. It was morning when we started and by the time we were done it was starting to get dark out.