Any episode, from any season. Not necessarily season finale, you could pick any random episode.
In my opinion: "I had an accident". Why?
Because surreal and random ending of this episode is perfect. :3
Even if those episodes both were terrible and got removed from time, we would still be living in a terrible timeline. Honestly, screw the world....A timeline without Sportz, Code Yellow, and Krusty Katering is a good timeline.