From what I've tried, pineapple and onions. I also hate shrimp as a principle so I'll add that to the list. I can handle anything else on my pizza that I've tried mushrooms or olives or whatever and liked them all but onions and pineapple are a no from me. Pineapples are just too sweet and clash with the taste but that's just me!
ahh that sucks. i used to dislike bell peppers a lot before, especially warm ones but yeah now i can stand most of them.. although green can be very bitter without the right things to go along with it.
I'm Jewish so I can't have meat on pizza as it is, but I once had beef with vegan cheese and the meat was just,,, ew. not sure how people eat it lol
I also really dislike
-Pinapple
-Onion
-Anchovies
-Olives
-MeatFeast styles
etc
Never had it, but sardines. I'm rarely picky about toppings, and I know that topping isn't even all that common (I think) where I am anyway. But still xD
The only topping I ever get on pizza is pepperoni lol I have pretty bland tastes soo for least favorite I guess any kind of fish/seafood. Shrimp pizza sounds and looks like a crime against humanity. Everything else I just don't care much for the taste (olives, peppers, etc)
One time, a pizza restaurant near my place sells a pizza with lots of marshmallow as the toppings. I didn't even try that but I know it must be gross. Even kids were not ordering that one. Later I found out that the marshmallow pizza wasn't selling well and ended up in the dumpster :/ Such a waste...