Chocolate. Started with realising aged 11 that the Christmas selection stockings with a Galaxy in were a bit shit, then hot chocolates got abandoned in favour of coffee - then I started having to take the taste of Cadbury's away with salt & vinegar Discos and a coffee or Red Bull (lots of very early morning commuting in winter meant I ate breakfast on the platform) then I stopped commuting and didn't have to feed myself solely from what was available at the only shop open at 5.37am. When I tried a piece of chocolate again, I just didn't like it at all and haven't bothered in somewhere around 20 years.
Ice cream. Not keen on sorbets, either. They are both too sweet and the ice cream - and not just the cheap ones, posh ones, too - are just fat and sugar.
Cereal. It's just sugar and reformed sawdust. Refused to eat Frosties or Sugar Puffs as a kid, had a piece of toast every morning before school (unlike 'every normal child', according to my mother), then realised there wasn't that much less sugar in the others on the rare occasions I was in a place where that was all that was on offer. And 95% of the nutrition listed on the back of the box was that provided by the milk, anyhow. I will happily eat porridge made with water, Weetabix with salted butter and, at a push, Shredded Wheat.
I agree with pizza - I make them and calzones when I'm feeling generous and they are very good, apparently - but I'd rather have a plate of good tomatoes sliced up with some mozzarella, some thinly sliced meat, olives, a tiny splash of olive oil and some fresh herbs.
Sponge Cake. I just don't see the point. Why waste flour, milk, eggs and butter by mixing it all together with sugar, just to cover the already overwhelming taste of sugar and fluff with more wasted butter corrupted by more sugar? At least a proper fruit cake tastes good with cheese.
Biscuits. What's the point? Sawdust and sugar - and then you're supposed to despoil a decent cuppa by leaving a layer of sugary grit at the bottom of the cup?
Custard. Meh.
Stuff in breadcrumbs. What's the point? For the manufacturer, plenty - they get to charge top dollar for a teaspoon of scraggy offcuts or the slops from the slaughterhouse and some breadcrumbs. Rather have a piece of fish or chicken. And now, people pay even more to get vague approximations of stuff in breadcrumbs, just so they don't feel as though they're missing out on some of the crappiest food.
I can't eat mango by itself, as it tastes soapy to me - if it's accompanied by other fruits, I can manage it. But I wouldn't choose it. Strangely, mango juice is fine.
Pretty much everything else savoury listed on here (Avocados, olives, egg, blue cheese, etc) are things that make up most of my meals, however. And liking coffee can be a natural thing - although it was very weak and consisted almost entirely of milk, I liked Mellow Birds coffee when I was three.