Your friends are really horrible people.

Simpsons – The Video Game
99.9 % Completed, Friend erased it while he borrowed the game.
Pirates of the Caribbean – The Video Game
99 % Completed, Game was stolen by a "Friend" and file was erased so he could play the game, despite 2 Empty files
Dragon Quest 9
Saved right before the last Boss of the Game, Friend was dicking around with my DS and deleted it "as a Joke"