I recommend doctor who!

If you don’t know what doctor who is it is basically a series of this alien named the Doctor who goes around saving the earth and people and planets and stuff in a spaceship called the TARDIS. The TARDIS stands for time and relative dimension in space. The doctor looks like a human but he isn’t. He travels around with a human companion. It’s a really good show and it has something for everyone. Sci-fi, action, superhero’s(the doctor), history, romance, mystery, etc. it’s the best show I’ve ever watched and it has two spin-offs and another one coming soon it is the 9th most biggest fandom. I recommend watching the 2005 series first but do what you want. Also it’s been running for 63 years making it the longest running sci-fi series ever.