Well, we have the "best meal of the year" list, so might as well start a "most disappointing meal of the year" thread. For me it was "The Square" in London. I was really looking forward to that meal but felt very let down by the service and miniscule portion sizes, even by tasting menu standards. I will have to say I received an incredibly generous offer from the restaurant manager when I wrote about my experience, so they are obviously paying attention.

Yours?

Went to Craft Steakhouse in Vegas to see what Tom Coliccio's place is like. Food was terrific. Overall the service was too, but I'm still very confused by one thing that happened. It sounded like it was a tasting menu, especially as the waiter tried to describe how the menu worked. He advised us to order two proteins as well as one side disk, and the meals also came with appetizers and dessert. It turned out that it was not a tasting menu, more like family style. So what they brought the two of us was a meal for 4 - 6 people. It was so disappointing because the food was exquisite but we had to leave much of it to waste because there was just so much.

I don't know if the waiter steered us wrong or we misunderstood him or what happened. At a restaurant of that caliber, I fully expect the waiter to say "hey, that's going to be a lot of food, are you sure you want to order all that?" but he didn't.

I've had that happen also and it is extremely irritating. Last year in the US we went to a chain called Buca di Beppo without knowing anything about it. The waiters did it right though, advising us that the portions would be family style and huge. That's just common sensical

I'm always on the alert for portion size when dining out in America - more often than not I streer clear of the appetizer as the main courses are often huge and sometimes both are as big as each other.
Obviously this is often less of a point in fine dining joints so I agree that the waiter really should have advised you exactly how much food was going to be on the plates you ordered.

For me it has to be The Greenhouse in London. Food was good if not a bit boring (and one fish was undercooked), service OK, but worth 310 pounds for one? Never.

Are most Americans really demanding portion sizes that large, or are the restaurants simply forcing patrons to buy more? Honest question. I've spent most of my adult life in Europe, so don't keep up too much with dining trends stateside.

310 is excessive. I've had full tasting menus with wine pairings at many restaurants in London and never even come close to that. Usually it is around 220-230, tops for a two-star. I think even the Square was only around 240.

I think most diners in anything other than fine dining restaurants have come to expect the fully-laden plate.
Even if they don't always eat everything on it - and I'm staggered by just how much food comes back on plates being cleared from table - I think it's seen as a value-for-money thing.
I remember years ago after a few weeks in the States craving nothing more than a crusty cheese roll with a bit of pickle in it.
When I ordered it in a roadside diner - and specified I wanted nothing else - it came with fries, crisps,coleslaw,a piece of corn on the cob,crackers.
And a bowl of soup.
And the crusty roll was two slices of industrial white bread - the only bread they had.
The waitress told me it was on the menu as being for light eaters !

My opinion as an American: most restaurants here cater to the least common denominator, which seems to be people with gluttonous tendencies. And as Showbizguru said, it's perceived as a value for money thing. I say this as someone who was raised that way (family of truck drivers, and silly guilt trips about starving children in Ethiopia), but now I prefer smaller portions and my biggest issue keeping my weight in check is my inflated sense of correct portion. I'm MUCH better than I used to be, but... fat just sticks with you longer the older you get.

It wouldn't be so bad if restaurants allowed you to order half portions, but most don't. It's really shameful how much food we waste.

Next: Vegan.

A fairly well-rated little place in Little Italy, NYC called "Parm" which has good food but on the night I visited at least unhelpful staff.

It was a cold, cold snap in NYC and the place was almost empty and they made me sit on one of the front bar stools to dine despite there being plenty of tables & booths for two.

Overall pricey and disappointing for me.

Plain oatmeal. Saddest thing ever.

Sepia in Sydney. Highly regarded apparently.

We paid more than we did at Akalarre in San Sebastian (3* FWIW).

Food was unforgettable, bland and mono-texture. Service was arrogant ("we don't give the menu until the end of meal so you don't have preconceptions"). Unfortunately this extended to napkins, which arrived at course 4, without an apology. Paired wines were picked for "uniqueness" rather than taste (picking a white grape from a red area etc. and bizarrely included only one Aussie wine...."food miles" anyone?). The first 5 courses took 2.5 hours and they then rushed the last 3 in less than 30mins, presumably as they wanted to close up.

Coi in San Francisco. Had the tasting menu. Two Michelin stars. Service was excellent. Food was of course made with skill and presented well, but almost everything seemed to be weird for the sake of weirdness. Lamb was excessively rare and almost cold. Overall a decent enough meal, but for the price and the expectations I had, I was disappointed.