What are your favorite time travel episodes of TV shows?

[Snoopy Fan 1,515]

Mine are:

SpongeBob: SB-129

Phineas and Ferb: It’s About Time

MLP: The Cutie Re-Mark

The Fairly OddParents: Father Time

Jimmy Neutron: The Tomorrow Boys

Danny Phantom: The Ultimate Enemy

Kim Possible: A Sitch in Time (I know it’s technically a movie but still)

Gravity Falls: Blendin’s Game

[Megas 27,777]

Not an episode but the Android Saga of Dragon Ball Z. Trunks has one of the most badass debuts ever

 

[Mothra 691]

First of all, this topic got my brain thinking about Xiaolin Showdown, a show I used to watch all the time as a kid and now that I have remembered it, I'm definitely going back to watch it again so thanks for that 

As for the show itself, I remember there was an episode where a character froze himself in ice and waited for it to thaw so he could see the future, and I think his 'future self' was in the same timeline as him too? I haven't watched in a long time so my memory is a bit fuzzy on it, but that was one of my first exposures to time travel plots, if not my very first

[Otaku-sempai 528]

Star Trek: "The City on the Edge of Forever" teleplay by Harlan Ellison.