I've seen star trek 4 times now (and heading back for a 5th) and the two scenes that make me laugh out loud are the one with Kirk and Bones and the classic numb tongue line...hilarious.
The other one is all Chris PIne... Kirk just got booted off the Enterprise for mutiny. He eventually meets up with Spock Prime and Spock introduces himself. Kirk pauses for a well... and then says "BS". Has me howling each and every time. Kudos to Chris Pine for pulling that off brilliantly