I do a lot of stuff.... like saying LOTS AND LOTS of Gollum quotes. One thing about that is that I can do it really well (or so people say) so I always friek people out when I do that.
Another thing my cousin (firefoot) and I do a lot is sing "Hey! Ho! To the bottle I go!...." and that usually frieks people out. Nobody gets our "strange" obsession!
Another thing I do is say the "You shall not pass!" when I don't want someone to come into my room. That usually keeps my annoying siblings away.
I can't think of anything else at the moment, but I'm sure I will later!