People who treat you snottily when you give them gifts of a lower quality than that to which they are accustomed.
It's a major pet peeve for me, and it's coming up right now because Thyme can be really nasty about things like this. I'm going to get her Braid for her Christmas gift, which I'm sure she'll enjoy and is within my budget. Otherwise, she seems to be sort of fundamentally wired to be socially interested in groups, not in any individuals other than a romantic partner. Since I'm not in her group of friends from college, I can't exactly go get her something that will be just the thing to make her feel even more included; and because she is so oriented to these groups, her interests are neither stable nor expansive. She's stuck in a position of constantly needing to rely on other people's opinions in order to form her own. Her stable interests are things like sex, drugs, and rock 'n' roll. Oh, and militant, downright offensive, "don't fucking mention religion around me unless you want me to shout you down because I hate God and churches and I hate people who have any sort of spiritual side or are anything but rampant materialists." I am actually not exaggerating. She doesn't say that, precisely, but she makes it clear that her position is one of violent opposition. To everything.
She also enjoys mocking country people in a way that I find uncomfortable. It's not traits, it's that they're people who live in the country and therefore stupid and bad.
I'm not saying there's nothing she believes in, but I am saying that I can't just give her something random that I loved (for example, Ender's Game--she likes books, she likes smart people, she likes sci-fi and so on, but I can't give her that book; I can't even give her books by authors whose work she's already liked!) and hope she'll enjoy it and we'll bond. Everything has to be carefully calculated in terms of extant structures and other relationships. Her current image of herself is "puzzle-solver," so I'm just going to get her the best puzzle-solving game I've found and hope she's finally satisfied.
And she tried very hard to steal my boyfriend, and didn't even have the power to say "I like him and I'm going to try to take him with my tits, okay?" to my face, because then I could have said "ah, yes, we are no longer best friends and I am not going to put you in a position where you get to try to take him every Sunday morning, and you don't get to act offended about that."
She was also the first person I came out about my mental issues to, and she told me I disgusted her and wouldn't use the name of autism, instead preferring to say "sore," which is Japanese for "that thing over by you and not close to me."
Sorry. It's a cacophony of feeling.