Lego Movie Blooper Reel – Funny But Not as Funny as Toy Story
I think that the Pixar movie "A Bugs Life" was one of the first movies I saw that featured a 'blooper reel' with outtakes and mistakes made by the animated characters during the making of the film. The Toy Story franchise also does a great job of making you want to stick around for a blooper reel during the credits...