I'm offended by people buy ripped jeans. I think there's little more insulting to those who cannot afford clothes that don't need mending.
I'm offended by people speaking in accents that are not their own.
I used to be horrified when most people describe women as bitches, dames, babes, chicks. Now, with a couple of exceptions dependant on context and tone, it doesn't bother me. Oddly when a man refers to his wife as The Wife, that just drives me nuts.
But, really, the older I get the less I'm offended by much.
It can be exhausting to ensure we respect the sensibilities of everyone we meet but, the older I get, the more important I think it is. And, the more that when those sensibilities are ridiculed by others, the more I see societal breakdowns.