Interesting thread, USA.
Two of the real disasters were of my own making:
Many years ago, when I was young and foolish, I showed up ah ... inebriated ... at the Sherry Netherland in NYC at 3 a.m. They checked me into a room that matched my condition; the surroundings the next morning were more ferociously awful than my hangover.
Drove Orlando-Miami one night in the early '80s ... ignorantly, I tried Route 1 after Canaveral as a `scenic' experiment. Reached the city fall-down exhausted around 2 a.m. & checked into a seedy LaQuinta ... a dirty, noisy and miserable little spot that provided me precious little rest.
Otherwise, a derelict-haven Best Western in Chicago, a cheesy Suisse Chalet in Connecticut (complete with mangy maid *walking in* at 7 a.m. shrieking `HOUSEKEEEEEEEPING'), and a cramped, sauna-like fleabag in Fortuna, Costa Rica are the worst of my particularly unpleasant recollections.
(and not to forget the supposedly elegant old Sands in Vegas; found a parade of ants along a wall, and the maintenance department arrived with Raid. Later, I looked under a bureau and found a mousetrap .... with a deceased victim. The front desk seemed annoyed when I asked them to remove it.)