What's the best out-of-canon story you've ever read or seen?

Our favorite characters go on and on forever. But sometimes, it's fun to see them reach a final ending. And sometimes, you want to see your favorite character in a story that would ruin everything if it happened in real life. What's your favorite story that's out of continuity?

Please include a picture or clip of this imaginary, non-canonical tale. And please tell us what it's called, where it comes from, why it could never be in canon (or was taken out of canon), and why you love it. Thanks!