I’m glad I’m not the only person who thinks honeydew melons exist mainly to provide filler for fruit salad. They’re not awful, but they don’t really add anything.
As for the Chinese and Latinos and dessert… This is a highly un-PC thing to say, but there are certain cultures that just don’t seem to “get” the concept of dessert.
My “looks good, tastes gross” food is whipped cream. If I order something in a restaurant I’ll ask them to hold the whipped cream, so this is only occasionally a problem. But every once in a while, a dish laden with whipped cream will make its way before me (perhaps I’m a guest in someone’s house, or perhaps I didn’t realize the dish had whipped cream and now the white mountain has been set before me), and I’ll sometimes give it a little poke and see if it still tastes gross. It does.
Oh! Oh oh oh! But the WORST is when whipped cream looks like ice cream. And I take a bite expecting the cold creaminess of vanilla ice cream, and instead get a mouthful of whipped cream. What a disappointment.
Add me to the coffee list. I get so sad when I look at all those yummy-looking concoctions at Starbuck’s, but it always goes the same way:
ME: Wow, that looks soooooo good!
SPOUSE: It tastes like coffee. (orders one)
ME: Can I have a taste?
(has a taste)
ME: Ewww, it tastes like coffee!
SPOUSE: Told ya!
I want so much to like coffee. I don’t like booze, either, so I’m pretty much screwed on all the social-lubricant drinks.
I am reminded of Steven Brust’s Dragaera novels. They have a coffee-based beverage called “klava,” which (paraphrasing) tastes like coffee smells. There’s actually something resembling a recipe for it in one of the books, involving eggshells and wood chips. People have made it; I’m not sure if it lives up to the hype. That said, my dad made “cowboy coffee” one time when we were on vacation in Florida. That uses eggshells to settle the grounds. It’s been probably ten or fifteen years since I had it, but it was some of the best coffee I ever had. I think the eggshells took some of the acidity out.
Also, for those of you who don’t like flan: Please send all your unwanted flan to me. 
Red bean paste is a common dessert in China. I don’t like it much myself but my wife’s family (they are Chinese) eats it all the time. It goes along with the theme of this part of the thread – it is only slightly sweet.
Marzipan is an interesting food, in my experience. Excellent marzipan, which is hard to find, is delicious. But anything less is disgusting.
Marzipan is one of those things that is frequently terrible because it is just made badly. I had some -good- marzipan at a local pastry shop, it was fairly delicious. Tastes like lightly sweetened almonds. Mmmm.
I like bitter things, apparently, so much of the “Yuk, tastes bitter” foods in here are on my tasty list. 
Mangos…well, odds are if you live in the United States, you’ve never actually had a GOOD mango, but that probably won’t account for violent distaste.
Uh. I don’t actually have anything on topic to share, because my list of foods I don’t like is really pretty short, and most of them don’t look appetizing either.
All that said, I’ve heard that if you consume something ~7 times, you’ll start to like it. I suspect it’s true, but that “consume” means more than “taste”.
A year ago I would have agreed with you. But earlier this year I had a recipe that called for honeydew, so I bought one at my local fruit/vegetable market. OMG. It was the best melon I’ve ever had - WAY better than cantaloupes, even perfectly ripe, sweet cantaloupes.
I dunno when this happened, since I hadn’t had one until this past summer, but you might want to re-try honeydews if you’ve got a good source for them. The ones I’ve been buying are utterly fantastic.
Strawberries can be hit or miss, too. As well as blueberries. A strawberry can taste like water or it can be super tart or it can be delicious and sweet. Blueberries are either tart or sweet.
Berries can be expensive so I’ve taken to cleaning and cutting mine as soon as I get them, then storing them in the fridge with sugar sprinkled on them so that they are evenly and artificially sweet 
Papayas are the biggest disappointment. Here’s this exotic fruit, from the far-flung tropics. And it tastes like wilted sub-par cantelope without the flavor. If you add some lime juice, then papayas can tilt back to “okay”. Without the lime juice they aren’t worth eating. Unless you are, like, hungry. I think the only reason papayas are all over the tropics is because a dinky little papaya bush will have 500 gigantic papayas growing on it, and people without much to eat can’t be picky.
We’re talking about ham & cheese sandwiches coated in egg batter & deep fried, right? If so, I love 'em WITHOUT the powdered sugar or jam. Just like I like my French Toast slightly salty/savory and NOT sweet.
Mildew.
Artichokes: big letdown-very little for lots of work. I’ve had them steamed, stuffed, deep fried. Always a big disappointment.
Soft shell crabs: hardly worth the effort.
Cucumbers: like a big pile of soap; tasteless.
Then also try: Welsh rarebit, and Croque Monsieur/Madame. Maybe slightly related is “the Elvis.”
I can’t remember if I’ve ever had them, but soft shell crabs require effort? To make or to eat, because don’t you just munch them down? But that reminds me, I like crab and lobster “okay,” but the cracking and extraction is not worth the effort, and then most people soak them in clarified butter and lemon anyway.
Artichokes: you’re not supposed to eat the sharp parts! :dubious: YMMV I suppose.
I am going to nominate chocolate-dipped strawberries (aka Shari’s Berries). They look attractive, in a fake, truffely way, but the combo of sweet berry and sweet chocolate, and sometimes additional white candy glaze decorations, make them so sickly sweet my teeth hurt just thinking about it. Two things that are fine on their own, but over-the-top nasty when put together.
This! I was going to say “What effort? You put them in a pan and fry them with butter.”
When you get right down to it, there’s not that much in an artichoke that’s actually edible. The heart, the lower bits of some of the leaves, and most of some of the inner young leaves, and that’s it.
Look at it this way: it is remarkable that you are eating a thistle, and not only not stabbing your tongue repeatedly, but you can anything on there, and it’s some damn good meat (IMHO).
Oh, and if it comes with the stem, I eat that too. It’s just like more heart, providing you cook it long enough.
Sidebar from the OP - artichokes are not what I would consider “yummy-looking”. I think it is remarkable that we eat them in the first place - someone must have been really deperately hungry to give it a try for the first time. Most of it is completely inedible, there may not even be wild animals that eat them, other than maybe some insects. They have to be picked at the right time, otherwise they are more flowerlike, and they need to be cooked very well. Who would have thought it was worth all the trouble to get at those hearts? (I do like them, tho).
Speaking of which - should anyone ever get to Berlin and go to a great department store called KaDeWe in the center of Berlin, they have an amazing top two floors of foods. Pricey, but the best of the best from around the world.
I mention this as in the produce section, they had a guy surrounded by fruits and vegetables from around the world - all of it looked gorgeous and exotic and what the fuck do I do with it? This guy showed you how to prepare it, which part was edible and which part wasn’t and gave tips on how to use it in recipes or just as-is. People would stand around him and just be in awe at seeing foods you have never even seen, let alone eat.
He sold tons of product!
(There is a niche market for someone to copy at an upscale store here!)
Just out of curiosity, has anyone here ever tried poi? I hear it looks yummy but tastes vile.