at the midnight buffet on the QEII once, I saw a chap loading up his plate with cakes, ice cream and what he obviously thought was (and what looked like) a slice of gateau, except he later identified it as a fish terrine; luckily, I wasn’t sitting in the line of fire when it all came spraying out of his mouth.
Of course hair in your food is nasty, worse when you’re eating in a restaurant, so it’s not one of the wife’s, and worse yet is when you pull the hair out of your mouth, and it springs into a short, curly shape.
Oh and I ate a rotten Brazil nut once, it was truly awful.
Not-quite-washed-enough spinach salad with sand grinding between your molars.
The texture of gefilte fish, if you didn’t grow up with it. Nothing wrong with the texture per say, it’s the wrongness when combined with the taste of the fish. Took getting used to.
Mistaking barbecue sauce for ketchup
Getting an iced tea and finding out that it’s unsweetened
Undercooked potatoes. When they’re even slightly crunchy it’s yuuuuck.
Gristle in your chicken nuggets. NEVER EVER EVER eat the infamous "McNuggets from McDonalds. 
Oh, and whenever something goes wrong with the Pepsi/Coca Cola machine. I had this Coke once that tasted like it had alcohol in it. Naaasty!!
Tomatoe butts.
Yes, tomatoe butts. Those nasty “cores” in the middle of the first few tomatoe slices that EVERY fast food joint fails to cut out. Are the employees at the slicer that lazy?
Frankly, tomatoes in general in restaurants are bad bad bad. I would rather just do without than have a slice of semi-pink mealy crap with a damn butt in the middle!
When the shredded cheese in my fridge goes sour. I hate it, it pisses me off. Dammit.
[sub]Yes, it happened today.[/sub]
Roast beef with that lovely rainbow veneer.
Wasabi may look like guacamole but it’s not.
yeah, mealy apples piss me off, too. i like my apples CRUNCHY (as in Crunchy Frog 
((yes, i just got off the Autopost-o-matic thread, howja know? :)))).
and you know unpopped popcorn? the kind that insinuates itself between pawfuls of popped popcorn? I HATE THAT! i’m biting into a niiiiice buttery pawful of popcorn, salty and fresh from the popper, and CRUUUUUUNNNCCCHHHH!!! right between the fangs. makes me cringe every time.
basically, i hate mushy things that are supposed to be crunchy and crunchy things that are supposed to be mushy. grrrrrrrrrr…
o well, off to get some nice, crunchy catnip.
MUUUUUSSSSSSSHHHHHHHH
AAAAARRRRRRRGGGGGGGGGHHHHHHHHHHHHH!!!
I love fruitcake! I look froward to this every year at Christmas.
I agree with jarbabyj about the ‘strong chicken’ taste. If the ckicken tastes too much like chicken it’s just gross.
I have problems with spaghetti sauce. If it is too watery, I can’t eat it. If it tastes too sweet or too much like tomatoes, it makes me want to puke.
I love pizza, but when it has excessive amounts of sauce, I have to scrape it off.
My youngest niece was hospitalized for a long period of time when she was 8, or so. She was tube fed, and was forbidden any food, to let her stomach heal. Her mom would stay all day, and then leave to go fix the family dinner. To soften the blow for a child who couldn’t eat, and desperatly wanted to, the family told her they were going home to some improbable meals.
My favorites: pez omelets, chocolate covered corndogs, coconut meatloaf, etc.
Then, about 3 years ago, we were all at the fair, and I SAW chocolate covered corndogs. They were in a heating rack, and everything. Ugh! Then, I discoved they were donuts on a stick.
Still, the imagined flavor still permeates my mouth at the memory.
Apricot
I remember watching a fellow student back in kindergarten once eating a small bunch of red grapes, with the vine and stem still attached. There was a big, fat snail oozing along the wreathy parts of the stem, and while he was oblivious to it, all I could do was watch in silent disgust and dread.
Eventually, he did notice it, and just plucked it off by the shell and set it on the ground without a second thought. I was expecting something more dramatic. 
I ordered a chile relleno once at a “mexican” restauraunt in central Idaho.
To this day, I’m still not sure what it was I ate at that meal. It sure as hell itself wasn’t a chile relleno. To me, there’s little that can be more unfortunate about the food you eat than not knowing what it is. 
…or one bad almond in the middle of a bag… Anyone for prussic acid?
What the hell is that stuff anyway?? It’s just not natural…
I ordered Iced Tea at an unnamed restuarant (rhymes with Schmapplebee’s) and received a LONG ISLAND Iced Tea.
I don’t drink alcohol.
Literally spit it onto the table and floor. “Sorry, Mom!”
Ordering “diet Coke” and getting “diet Pepsi”. Yes, it REALLY DOES make a difference to me!
Now I ask if they serve Coke or Pepsi Products. If the answer is “Pepsi”, then I order Iced tea…
…and hope that the above doesn’t happen again.
I used to live in a rather famous rooming house which had a common kitchen shared by all nine residents; and thus was crowded with a plethora of accumulated silverware, dishes, pots&pans, etc. My brother was over one night and we had ordered a pizza delivered. Deciding it to be a bit bland, I went out to the kitchen to see if I could find any pepper flakes on our crowded spice shelf. Not quite, but there was a shaker that proudly proclaimed itself to contain ground red pepper (think ceyenne). So we sprinkled it liberally all over the thing, and upon digging in found it had imparted a most…unusual…flavor to our pie.
Turns out someone had used all the pepper and refilled the container with cinnamon. Having spent all our money on this large three topping monstrosity, we went hungry that night.
I have my own kitchen now.
Not really a flavor thing, more of a moral issue…
Pink lemonade
I generally despise carbonated beverages, and I try to limit my caffine intake. So, when I go to a restaurant, I often order lemonade. However, I will not drink that mistake of the devil “pink” lemonade.
Could someone please explain this crap to me?
Or, depending on your tastes,
Biting into one of those weiner-shaped doughnuts (long-johns) expecting, yummy, rich, luxurious Boston Cream (nothing even remotely Freudian here!) and getting that fluffy white, sugary, underwhipped cotton-candy-like crap instead! Bleeeaaaggghhh!
Fenris
A real Monte-Cristo sammich is a work of art, a thing of beauty.
Shaved slices of ham, swisss cheese and turkey are put on egg-dipped toast (like french toast) that’s been sauteed in butter. Sprinkled with the tiniest dash of powdered sugar with raspberry jam for dipping. Yum. Pure ambrosia.
However…
An evil trend has reared it’s head: Deep-Fat Fried (or French Fried) Monte Cristos. Bleach. Same basic recipe, but instead of getting the french-toast texture and the buttery/eggy flavor associated, the sammich is dipped into something like beer-batter and deep fat fried so it’s crunch and oily and flavored like used-grease. Eeeewww.
And
There was a Chinese-food dish. Shrimp With Crispy Walnuts. The shrimp were coated with the most delicate, thin, coating and fried (silked, I believe it’s called). The walnuts were covered in sugar and caramelized so they were just on the border between sugary-and-bitter/burned. The brocolli was steamed but still crisp. And there was this intensely flavored, slightly spicy brown-sauce over the whole thing. It danced a fandango of love with your taste buds. It was big in Chinese resturants in the '80s.
And no-one makes it anymore. Which, I suppose, is fine, but they haven’t retired the name, they’ve given the name to an abortion of a dish. The shrimp are tempura-battered and fried, so they’re buried in dough. The walnuts are sugar-coated. The brocolli is gone. And the sauce. <shudder> The sauce is made of orange-juice and either mayo with sugar or Miracle Whip. And soy-sauce. Mayo has no place in Chinese cooking. And the combo of oranges, miracle whip, sugar and soy-sauce mixed together could replace ipicac
And every time I go to a new Chinese resturant, I have to grill the waiter/waitress to see if the Shrimp with Crispy Walnuts is the real thing (I keep hoping) or the vomit-inducing mayo thing.
Fenris