Too many to list. Lots of things my Mother fixed that I would love to have the chance to eat again from her hands that I disliked as a child: Mature green beans cooked to death in fat; hard non-sweet corn bread; strongly flavored greens that to my current tastes are perfect; wilted lettuce (spring lettuce doused with hot bacon drippings and vinegar) that today would be a delicacy to me; stewed beef (But not stewed tomatoes!); believe it or not, apple cobbler; rhubarb-strawberry pie; sour cherry pie.
Fish. I could eat some processed fish foods as a kid, and did like shellfish, but couldn't abide a piece of cod or haddock or hake or.... whatever. One day it changed suddenly. Out of the blue I decided I wanted fish, and thoroughly enjoyed it.
Spicy foods. I didn't find them tasty, just painful. Jerk sauce was the gateway, and gradually led to an enjoyment of spicier foods, but I still seem to enjoy a higher tolerance for hotter Caribbean food over hot curries for some reason. In fact it's probably more accurate to I have an inconsistent tolerance and enjoyment for hot spicy foods.
Several vegetables, but that's more to do with the fact I enjoy the way I do them, as I don't overcook them.
There aren't too many, as I've always enjoyed all sorts of things and been an adventurous eater. However, one big one is anethole, the distinct flavor and aroma in licorice, anise, fennel, etc. Up until 25 years ago or so, I wanted nothing to do with that stuff. Then, a switch flipped, and I've quite enjoyed it ever since. Go figure.
A lot of vegetables. Growing up I didn't ear many. What helped was that Dad didn't like vegetables and he wouldn't make us eat something that he wouldn't. Now I like most vegetables because I didn't aquire and hatred of them by being forced to eat something I didn't like. Put peas on my wife's plate and they end up across the room!
There are a few, though, as the youngest of 4 boys I ate was I was told. I didn't like uncooked tomatoes until I was a teen. Eggplant is something I didn't try until adulthood. But as of now, the only two things I don't think I like are okra and pickled eggs.
When young we have a natural aversion to bitter. An appreciation comes as we mature so any bitter foods were an acquired taste. As much as i loved the look of mini cabbages and wanted to eat them as kid i couldn't do it. Now bitter is great so things like brussels sprouts, rapini, dandelion greens, rutubaga, coffee, blue cheeses, no problems.
Most cooked vegetables i hated growing up, corn and broccoli could be fine, that's about it. Now, cooked the way i like, i can enjoy most of them except a couple sweet ones such as winter squashes or sweet potatoes, flavour and texture still can't be overcome, even the smell of beets or beet tops cooking will still make me gag and there was no dessert until your plate was clear, brutal.
They fed us canned cooked spinach in the cafeteria in grade school. I don't care how many times I saw Popeye squeeze that can and watched it pop out and go into his mouth, I wasn't going to eat it. I'm still not a huge fan whens its over-cooked. I like it in a dip or inside an omelette. Raw is how I like it and grow it in my garden.
Liver is a good example. Did not like any kind of liver as a kid. Love it all now.
I am convinced Brussels sprouts just taste different these days, even taking into account better preparation these days. I remember them tasting distinctly sulphurous (sp?). It has been a long time since I have experienced that taste in them.
Used to hate fish with bones in them that one had to pick out. Can tolerate that pretty easily now.
Olives were an odd one for me. I do not remember black olives as a kid. I apparently loved green olives for a time when I was really little and then hated them. Now I love all olives.
I do not think I am fond of winter squash even now. I tend to think I have never liked eggplant, but I probably actually like it fine.
Scotch is a fine example of an acquired taste. Bourbon, too, in my case. Always liked beer, even as a very young guy.