My preferred genre of Manga is Shonen cause I always like how high character's powers can go and I am a sucker for cool bad @ss form changes. I've been reading manga most my life with my current list of manga I try to stay up to date with are Berserk, Jojo (Part , and One Piece. Eventually I'll get around to My Hero (anime caught up), Blac...
Any kind, from One Piece and Bleach to the various Isekai.
If you start at Chapter 1, of ANY Manga, and keep on going through, chapter by chapter, you WILL eventually finish it (Or find out that it's no longer published/translated!)
There will never be a point where it says, "To find out what happened here, you need to buy this OTHER series!"