Monsters, Inc.

In the Pixar movie Monsters, Inc., Boo, a two-year-old girl, is a source of a lot of humor in the movie. Monsters, Inc. is a company in Monstropolis where workers scare little children by "activating" their bedroom doors on the Scare Floor of the building in order to gain energy from their screams. When we first meet Boo, we don't know her name, especially since she barely speaks, but Sully (blue) ends up naming her Boo. She calls Sully "kitty" repeatedly while he tries to get her back through her door and into her room (monsters think humans are lethal). She's persistent and doesn't go back, so Mike (green) and Sully have to keep her a secret from everyone else. This results in an extremely funny animated film. At the end of the movie, Sully becomes CEO of Monsters Inc. and solves the energy crisis by creating the Laugh Floor where workers make children laugh instead of scaring them. Below are a ton of clips of Boo from the movie.

Life is Beautiful

In this movie, Guido Orefrice hides his son from the Nazi guards in the camp.  He sneaks him in food and attempts to keep him laughing as much as possible.  Guido convinces his son that the camp is just a game, and the first person to get 1,000 points wins a tank.  He tells him that if he cries, complains, says he’s hungry, or misses his mother, he will lose points.  Though this is lying, it is a good way to keep his son’s spirits up throughout this traumatic event in the concentration camp.  This displays Guido's optimistic view on life.