There aren't many specific food items that I hate. Right now I can only think of Brussels sprouts and pickled fish.
But there's an entire group of foods out there that has no reason to exist.
Spicy. Fucking. Food.
Maybe it's not all that weird, but I avoid spicy food if at all possible. I mean anything spicier than a very mild salsa. I don't care how good your food is supposed to be, if there's even the slightest burning sensation involved, it belongs in the garbage. Spiciness ruins food completely by overpowering any flavors that I might enjoy, and every single spicy dish I've ever tried would have been so much better without the pain. I'm not saying bland food is the way to go. I season my food liberally and use herbs all the time, because I like tasty things. It's just that spiciness is not a flavor, it's a pain response, and that's a ridiculous thing to want from your food.