Fully SUBJECTIVE
1. AOT- (Gave literal death threats to VA, fought among themselves for the ending)
2. MHA- Shipping Wars, one of the worst fandom that butchered the show with their own hands)
3. Solo Leveling- (I personally hate them)
4. Demon slayer- (new fan harassement, elitist, spoilers and shi)
5. Naruto- (Gatekeeping and belittling new anime shows, hate for women in general and its worse)
I might just have to make a new list about naruto fans hating on womens
6. Dragon ball- (goku solos, goku vs goku vs goku vs goku)
7. One Piece- (fighting among themselves, 1000eps = greatest show ever, biased asf)
8. Mushoku tensei- (diddy's)
9. Bleach- (Gatekeeping and belittling new anime same as naruto)
10. Gurren lagaan- (for them world is all shining and rainbows

Dehonarble mentions- Fmab (its not toxic its just loyal, they are proud of their show and dont go on comparing to other s h i t s, unlike no 1 fandom ik about) Jojo (again loyal and proud), fairytale (very aggressive and defensive at the same time)