Everthing, as long as it's not Yaoi/ Yuri/Hentai/Adult/Ecchi/Isekai
But for my personal references, as I grew older (now in the mid-20s). My taste can change depending on the mood.
I really love seinen.
Especially :
1) Historical (whether it is fiction or non-fiction), for example : Napoleon, Vagabond, Imuri etc.
2) Something that inspires/self-reflection/realistic/heavy stuff, for example : Yomawari Sensei, 3-gatsu no Lion etc
3) Something light with slice of life, for example : Yotsuba, Azumanga Dioh etc.
Then josei, shounen, romance, fantasy and many more.
I'm good as long as it is not cheap, trash story, childish.
I can't really explain it because each series presents different vibes. Sometimes I feel comfortable, interested, curious, and so on.
I give a chance to read it, if I think is good then it's good and bad is bad. Simple as that. I'm quite observant but not elite myself. I'm just enjoy which is interesting and has amazing story.