I feel like I keep finding new flavours I love and hate constantly, so it's hard to pick only a few but I'll try...
One of the best things I've ever eaten was my grandmother's homemade karelian stew. We had it every Christmas and it was just so full of flavour. The beef wasn't even the best part because the broth was so delicious. Absolutely amazing. Unfortunately my grandma passed away some years ago and it's a flavour that will forever remain in my memories. I'm a vegetarian these days, and it's the only meat dish I miss.
Generally though, when it comes to specific flavours I absolutely love blue cheese. But not just any blue cheese, it has to be a specific brand because it has a softer flavour than the others. Some of the cheapest blue cheese also tastes like what sock sweat smells like and that's not what I want at all, no sir!
Recently I've been absolutely loathing cilantro. Or coriander... Wait, which is it? Anyways, I seem to pick up if there's even the smallest amount of it and it ruins the whole meal for me.
The absolutely worst taste was this stomach medicine I had to take once. It was in liquid form and it was vile. Absolutely horrible. I feel like it was really evil to have a stomach medicine taste so bad because it just made me want to throw up.
(On a sidenote, I once got strawberry flavoured sedative at a hospital and they gave it to me in a pink syringe with cartoon characters on it. I was an adult already but I now consider that the best medicine I've ever gotten. Adult sedatives should also be strawberry flavoured.)