I chose the title carefully... not necessarily worst-ever meals, but considering the whole experience (including in some cases the extended period of discomfort afterwards).
So... we visited Tucson, Arizona. Our main reason was to go to an Indian Rodeo in Sells on the Tohone O'Odham reservation, which was quite an experience. But that's not important right now. On our first night, we asked the hotel to recommend a restaurant. We had trouble finding it, because it was nowhere near the town centre, but in the hills quite a way to the north in a fancy golf resort hotel kind of place.
There's one advantage to the location... Tucson is quite a pleasant small-ish town, but one of the main trunk rail lines goes literally through the middle of it, with level crossings every few hundred yards. This means that several times per hour, a mile-long freight train passes through, horn blaring, not just audible but loud through the whole city. All night long. Amazingly, you get used to it.
Anyway, it was obvious as soon as we arrived that this was a very pretentious place. It just had that air about it. We both get easily irritated by places whose pretentiousness greatly exceeds their quality, and this place had it stamped all over. We took our huge, pretentious seats, in the pretentiously decorated dining room, led by the pretentious hostess.
As we suspected, the meal was so-so. Nothing wrong with it, but nothing special either. For half the price and a tenth the pretentiousness, we would probably have quite enjoyed it. And of course the wines were over-priced. A dead giveaway for a restaurant that takes itself much too seriously is that the wines are priced at about double what you'd reasonably expect. I can only suppose that people who like pretentious places want to pay more for wine, I guess it makes them feel superior or something.
What elevates this place from merely annoying to the short, distinguished list of The Best of the Worst, though, was the total contrast between the airs and graces they gave themselves, and the actual quality of the service. Our waiter was a kid, maybe 19, who had clearly received little or no training. Probably he'd learned on the job at Denny's or some such, then managed to talk his way into a job at the restaurant. The service would have been perfectly acceptable, if we'd been at Denny's and paying Denny's prices. He had no idea how to serve and kept getting things wrong.
One thing which drives my wife absolutely nuts is when she's still eating and the server says "You still workin' on that?" It would annoy her even in Denny's, but frankly eating a meal in Denny's is more work than pleasure so it may make sense. At a fancy restaurant, even a legitimately fancy one, it is just so inappropriate. Maybe a Jeeves-like "Is Madam still profiting from the enjoyment of her repast?" would be better, but simply observing that she has not put her knife and fork down beside each other, and is still chewing, and saying nothing at all, would be even better. You can guess, of course, that our Denny's waiter came by not just once but several times to ask, "You still workin' on that?".
Finally I ordered dessert, I can't really imagine why since by then we were thoroughly fed up with the whole place. The waiter served it, but didn't bring anything to eat it with. After waiting a while - I wasn't in a hurry anyway - I finally helped myself from the next table. Nobody even noticed.
We didn't leave a tip. That doesn't happen often. We were just relieved to escape the overwhelming pretentiousness combined with total ineptitude.
The next day was delightfully different. We had lunch at a diner in the middle of nowhere on the way to Sells, for less than the tip would have been the night before. And in the evening we went to a very unpretentious restaurant near the university - it pains me that I can't seem to find it now, and it probably isn't there any more. The tables were small, the waitress was friendly, and the food was excellent. What a contrast!