Terminator: The Sarah Connor Chronicles. I'm not a big Terminator-head, only seen half of the movies, but that was the version of Terminator I really got into.
TSCC ENDING SPOILERS, STAY OUT
The decision to end the show by having John jump into the post-apocalyptic future was wild, from a production standpoint. You have this show that's in permanent danger of being cancelled and you go "What if we set up our ending so the next season is guaranteed to blow the budget because we can't just film in present-day California any more?" It was a great hook, but I wonder whether they could have gotten a third season if they'd presented a smaller target.