The most hilarious Worf moment ever (at least on TNG, there are many other great moments on DS9 as well) is in 'The Dauphin' in season 2. Anya orders Pulaski to kill a sick patient. And turns into a huge bug eyed monster which Worf grapples with for a few seconds, until a few non SAG security guards show up and strike dramatic poses. Worf waits til she morphs back into an elderly lady before he decides to try to hit her. It's freaking hilarious!
Also, Troi was definitely the master of the 'No shit, Sherlock' moment