Gauges. I generally love piercings and tattoos but these squick me out.
Luluroe/Pure Romance/Doterra and anything else people think their FB friends would be "really interested" in buying.
Keto. God, followers of that diet are worse than even the most crusading of vegans!
Deliberate offensiveness disguised as "telling it how it is" or "not being PC". Racism and sexism and poor taste aren't a virtue; stop pretending they are.
And as someone else upthread said, high school graduation requirements designed to check the boxes on a Harvard admissions checklist. There's nothing wrong with stopping short of calculus, or with wanting to focus on the arts, or with pursing a skilled trade. I don't know who decided that the bar for graduation should be set at able to apply to highly selective colleges, but it isn't doing just-average students or those who learn best in ways that aren't suited to the classroom any favors.