If this count, I sometimes have a hype aversion. The more hyped a thing is (unless I have followed it before it's got known and/or genuinely like it), the more I don't want to check it. Especially in mainstream media, I often connect hype with a mere marketing tactics and not the quality, and at times I don't fit with mainstream taste. Sometimes it makes me think twice to check popular or mainstream stuffs because of sometimes I associate popularity with being overhyped and disappointment. I know I might be missing something that I would really like just because of this, but sometimes I can't help it.
Sometimes I nitpick on character design, especially if it's unrealistic for the setting or just plain silly. It doesn't make me dislike the series altogether, but just have a single nerve in me screaming how it could be better everytime I see the characters. Also if I only can distinguish the characters by hair and clothing (as they all have same faces, build, and skin), or they are all being similar and it doesn't serve a purpose in the story (e.g. not a clone or related) then my mind won't shut up.
Just like you, I also nitpick on art-style. I'm more wary of art style that is commonly use in shōjo manga or any moe cutesy art style, I associate that art style with romance stories and I don't like romance.