Processed cheese in those little plastic-wrapped individual slices. Especially American.
Most of the things that I can't stand have been mentioned. I'll add this to the list: I have a mother in law that 1. is a lousy cook, but thinks otherwise and 2. saves leftovers until they turn green, scrapes off the mold and uses them. My grown children caught on years ago and forbade their kids from eating anything in or from her house. One of her favorites is to grind stuff up and make "delicious soup". She loves to save leftover Chinese food for endless re-use and combining with anything else that's around. One of my grandsons told her that he liked rice pudding, so she made some out of archived vegetable fried rice. The best part was watching him avoid having to eat it front of her. She's now over 90 and these habits are exaggerated, but my skin crawls when she pulls food out of the refrigerator. My wife and others purge it periodically for safety (if not sanity) reasons. She's been like this for as long as I've known her (50+ years), so it's not an old age thing; my late father in law (doctor) claimed that the reason for his heavy drinking was to protect himself. Long winded answer, but this type of food related behavior is hideous.
Borscht and Schav.
Uni/sea urchin is a true delicacy to me. When fresh and good, I am not sure there is anything I like better.
Hakarl and mayonnaise. And between those two I'd rather have mayo.
Where did you find Hakarl? I never found any in Iceland to try, though I wish I would have looked harder for it. I doubt I would have enjoyed it, but it would have been worth it just to say I had.
I'm in culinary school and am doing my apprenticeship hours at an upscale fish house. Our executive chef fermented some for about six months and we all tried it just to say we had. It was an absolutely horrible experience.
I grew up with a mix of a traditional and somewhat non-traditional diet since my Mother is from the PI. The two things that absolutely, positively revolt me are:
Balut - A developing duck embryo. I've had them several times and can't get past the first bite. Imagine the strongest egg you've ever had x 1000 with soft bones, beak, and sometimes feathers.
Durien - A spiny fruit that smells to me like rotting onions, sewage, and dirty sweat socks. I know some people describe the palate as being like custard with an almondy flavor, but it to me is even worse than balut.
Give me all the Spam, organ meats including Fois Gras, and insects as these two are the only two things that I will give a refusal. I have an immediate physical response to both when they hit my palate.
You should allow yourself some from time to time. If you totally abstain you may end up binging on it.- Except KFC. I want some, but I have willpower
I love Uni. I can't always get it at the Sushi bar I frequent, and even when they have it on the menu, its expensive. I like places where I can order it one piece at a time instead of in pairs, but that option isn't available at the place I go to now.
I always save it for the end of the meal as a dessert. I will finish up everything else (I usually order a Chirashi) and then cleanse my palate with water and Ginger. I eat the Uni slowly, taking time to let it dissolve in my mouth, and then I can still taste it for about 30 minutes after I leave the restaurant. Although they usually serve it on top of a cake of rice wrapped in Nori, I leave that behind so it doesn't spoil the taste of the Uni.
There was a place in Baltimore that had LIVE urchins in a tank behind the bar, and they would catch one and serve it to you. I went to this place a couple of times wanting to try the live Uni, but they never had any when I was there. Still, the rest of their menu was superb.