In no particular order: Highlander (in continuity with The Series), Transformers (in loose continuity with G1 animated series and movie or reboot based on that gen), or Inhumanoids (reboot). https://twitter.com/PackardShow/status/1385986978043371520

Literally just the series. https://twitter.com/TheSourSavior/status/1386336881898631168

Highlander: The Series, particularly after the first season, was a version of the Highlander universe designed to be open-ended. The Gathering was an unproven and unprovable theory, as were most aspects of the Game. The Paul movies, in my opinion, answered too many questions.

Not sure what medium I'd want to write for Highlander in. A TV continuation would need all-new characters, an unlimited CGI budget, or some new wrinkle to the lore where all immortals visibly aged for a few years.

Going down a Chris Latta wikihole related to this thread led me to this absolutely accursed gem of regional children's television programming that I had no idea existed: King Koopa's Kool Kartoons.