We’ve done personal preferences before…now let’s see how well you know your SO.
Ivylad can’t eat citrus. The vitamin C makes him break out in cold sores.
He doesn’t care for tomatoes, but will eat them chopped up on a taco.
He doesn’t like bell peppers.
She doesn’t care for mushrooms, but really dislikes eggplant. I’m slowly increasing her tolerance for garlic.
Ketchup. I swear, it’s like a long-term enmity.
Oatmeal. She said she had it every morning when growing up.
Onions. She has nothing against the flavor - it’s all textural.
Bacon. Mayonnaise. I think she’s not human.
Lima beans and, by extension, succotash. I married her anyway. More beans for me.
Ivylad doesn’t like green olives, which is fine, because I do.
I don’t like black olives, but he does, so again, all fine. 
Suburban Plankton doesn’t like dill pickles. Neither does the kid. All the more for me!!!
^ I haven’t seen a pickle barrel in 40 years. Do you suppose there are any still around?
Anything with fat in it.
Anything “fried.” I’ve explained that “sautéing” is not “frying,” but she’s not having any of THAT.
Any Central or Eastern European cuisine.
Southern U.S. cuisine. BBQ is acceptable, but ONLY chicken or tofu.
Anything with cream or butter. Olive oil ONLY.
Any soups aside from Greek-style lentil or white bean. NO MEAT in them; olive oil ONLY.
Anything en casserole.
Potatoes in any form.
Any pork except tenderloin, which meets her leanness standard.
White rice and pasta. ONLY whole grains and bean-based pasta.
Lately I’ve been making my own personal dinner, and just grilling her a lean piece of beef or chicken or fish. She makes herself a salad. NO DRESSING.
My husband hates macaroni and cheese. He says he saw some experiment in school involving yeast that just grossed him out permanently, and that’s what he associates it with. [tiny violin]So that’s why I hardly ever get to eat one of my favorite foods…[/tiny violin]
Also peas; he doesn’t like the way they pop in his mouth.
I don’t like mac and cheese earlier. (Someone way back posted a link to an article linking food dislikes to some sort of childhood bad memory.) I have a distinct memory of vomiting up mac and cheese as a child, so that’s it…no mac and cheese for me.
Which is strange, because I like pasta and I like cheese. Go figure. The brain, she is funny sometimes.
Holy shit, this is grounds for a divorce! 
My SO also doesn’t like dark meat, but I don’t like white meat, so it works out. White meat has no flavor…!
She’s not a big fan of celery, but I don’t think I’ve run across anything she actively dislikes, other than most fast food.
That’s what I said to her 10 years ago, when she announced that she’d suddenly become “allergic to garlic.” What kind of second-generation Greek becomes ALLERGIC TO GARLIC?
But BBQ is pork…
I get the impression she doesn’t like to eat much in the first place, if her list is that restrictive of anything that actually has flavor.
My SO is pretty catholic in what she likes; her big triggers are some of the more egregious artificial flavors (she can’t abide flavored coffee, for example), and some particularly strong flavored things like gorgonzola or blue cheese. She’s not at all averse to spicy/picante foods, but she doesn’t much care for hot sauce- I think it’s the combination of heat, pepper flavor and vinegar that she doesn’t care for.
So ultimately, I’m totally on my own if I want classic Buffalo-style hot wings.
Neither of us is very fond of offal, although I’m more likely to not gag if served pate or something along those lines.
Oh… she won’t eat beef enchiladas with chili gravy anymore. Something about the time we had that for dinner while she was pregnant, and then she had such a violent morning sickness (in the evening) bout that she puked it up through nose and mouth at the same time.
— Okra, but we’re on the same page about that, so it’s all good.
— Pickled relish, because she’s some sort of insane person.
— Sausage gravy (see prior comment re insanity).
— Raisins, because she’s not that insane.
Considering that The Incomparable Sunflower comes from a household where her father was a very super picky eater, she has made great strides in the 44 years we have been a couple. We all have things that we like and dislike, but she has been more than willing to try things.
She will not (after a few tries at it) eat Beef Liver. At a Crawfish boil, she just said no.
We had an episode of food poisoning from Famous Dave’s and she will no longer eat coleslaw.