{Poll added] Name an animated series that rivals Steins:Gate or Rick & Morty?

[DroidKnight]

John2290 said:

DroidKnight said:
Just thought I'd give it a mention, didn't see anywhere in here.

Golgo 13.

A film? Is it as serious as it looks or does it have homour and good vibes?

A film and 4 seasons.  4th best selling Manga of all-time. Longest running.  Kind of serious since it's about a hitman.  It has it's moments.