Whether letting off steam, showing their goofy side, or just plain losing control, I love it when we get to see TV characters laugh! I must say right off the bat that Laura Roslin and her pre- debate giggles (from Battlestar Galactica) should be high on this list, but I couldn’t find a video clip of the scene. She definitely gets an honourable mention, though.
#5: The Doctor and Rose (Doctor Who)
Rose has a lot of great laughs with the Doctor, especially Ten. This one is from
the beginning of “The Impossible Planet” (2×08).
#4: Richard Castle (Castle)
Castle’s maniacal laughter from “Vampire Weekend” (2×06).
#3: Data (Star Trek: The Next Generation)
As a parting gift, Q grants Data one laugh attack in “Deja Q” (3×13).
#2: Adama and Tigh (Battlestar Galactica)
The two toughest military officers get the giggles in “The Passage” (3×10).
http://www.youtube.com/watch?v=bnoEgNW1kb0
#1: C. J. Cregg (The West Wing)
This hysterical scene from “Privateers” (4×18) has C. J. unable to control herself when she
encounters an angry but influential supporter with a funny name.
As I said, I love seeing characters embracing the power of the funny bone, so please add some other great giggle-fests to the list!
The Viewing Party 
This has got to be one of the great giggle moments in film. Enjoy
That’s a great one! Thanks for sharing!