I think being or wanting to be an artist/writer/author is pretty popular. Bonus points if part of them being a successful author is kind of a secret identity if they're not trying out. Among others I come across quite often are:
Teacher (let's not forget sensei)
Bookstore related
Chef
Detective
Cafe or restaurant related. Oftentimes waiters.
Actors...do they count? Though modeling seems to be fairly popular. May or may not be but I know I'm guilty of it haha.
Funnily enough, this topic made me realise my character's don't really have an occupation o<