Oh, for me it has to be this awful soup we were served one time we were in Riga. It smelled like a compost heap, looked like a compost heap and (unfortunately I was forced to taste it as well) it tasted what I imagine a compost heap would taste like. Worst of all? EVERYONE else around my table loved it and claimed it was the best thing we had been served while we were there... Contenders for second place would have to be the weird grey goop we were served one of the other days (at least that the others agreed tasted awful), oh and garlic bread is pretty awful for me...
To me it is meatloaf. I like most vegetables but meatloaf is -even with bacon and cheese- an absolute NO for me. And add liver on the list as well. When my mother was baking Liver it was a tough time for her to make me eat it.
Anything with a fishy implication. Whenever a piscine scent makes its way to my nose or mouth, my senses go in seizure mode, and my stomach churns from revulsion. You don't want to know what happens once anything fishy goes down my throat.
Can't remember the name but my sister brought home some Chinese candy when she was over there earlier this year, some sort of white Jelly that tasted like milk mixed with bad sugar.. ughh, never again.