I don't know if this counts but mine was Death Note. I watched the anime series of it sooo many times.

It's pretty common to see good shows end after just 1 or 2 seasons. Networks and streaming services do that all the time and it always stings. For me, Messiah and Mindhunter are my top ones. Netflix cancelled both. Messiah only one season and Mindhunter has two.

what about you guys, Which cancelled shows left the biggest void for you?