I ate beef tongue once . . . under extreme duress. We were visiting some country cousins on the back side of eastern Arkansas; near Palestine, I think. They served something I didn't recognize. One of Mom's uncles told me it was "cow tongue." Mom said she would personally kill me if I did not eat it, so I did. Never again. It didn't taste that bad, but I don't need to eat a cow tongue to do a passable moo.
Other things I simply cannot eat: boiled okra and jello, for the same reason. I cannot eat things that slide down before I swallow. Nothing wrong with the taste, but the texture makes me want to ralph.
The worst thing I've ever eaten: rubarb pie. My best friends mom is from southern Minnesooooota. She's a good cook, but the rubarb pie was just bad. BF said that was because you couldn't buy good fresh rubarb in south Arkansas (in the early 70's).