Here is a short list of things I don't like, never liked, never did like:
Offal in general
Any anal part of any animal
Rocky mountain oysters
Blood [insert dish here] (sausage, pudding, soup)
Products made with aspic
Now, I consider myself adventurous. I like octopus and squid; I've eaten and enjoyed beef tongue; I've eaten raw meat and eggs (steak tartare.) It's just that some things are too revolting or make me too squeamish to eat. It's a mixture of the texture and taste (liver is hideous in both aspects), or sometimes just texture (aspic) or just taste (blood sausage.) Beyond some of these, the worst of the worst, I generally consider myself a non-picky eater and enjoy a great many dishes and cuisines. I'm not above stooping to try something like eel or hakarl, even if I think they're gross, but I do have a few "will not eat" foods, regardless of the situation. I don't care if the Queen is serving it, I won't eat liver.