Nintendo and developer HAL decided to have a little fun when they remade the Super NES classic Kirby Super Star as Kirby Super Star Ultra for the Nintendo DS back in 2008.  Play through to the ultimate end of the entire collection of Kirby games and complete The True Arena mode and you'll unlock a special blooper reel video of Kirby, King Dedede, Meta Knight, and other characters from the game attempting to perform their parts in the action and screwing up royally in some fashion.  It's all scripted, of course, in the manner of Pixar's outtake collections at the end of some of their films, but it's still charmingly entertaining.  All in all, it's not a bad way to cap off the last of the game's unlockable content.