The Dead Zone/YMMV

Complete Monster: Greg Stillson and Frank Dodd.
Hilarious in Hindsight: Martin Sheen as foaming-mad mid-westerner President Stillson during the "the missiles are flying! Hallelujah! Hallelujah!" scene is especially funny due to his later role as the ideal Coastal Liberal president, President Bartlett, in The West Wing.
Memetic Mutation: "THE ICE! IS GONNA BREAK!"

Hilarious in Hindsight: In a Season 2 episode, Johnny is hit by a car while saving a child. He wakes up in the hospital and asks Bruce if it's 2009 (i.e., if he's been in a coma for ANOTHER six years.) Bruce deadpans "no... it's 2011." Johnny then asks if the Red Sox have won the World Series yet. We now know that in fact they have won it twice in the period Johnny's second coma would have covered, adding an added punch to this joke.
Ear Worm: The credits song followed by "No! Yes! No! Yes! NOOO! Yes! You're grounded.". You'd be surprised how much that can get stuck in a person's head.