Chocolate in America is just grim, on the whole. See's/Godiva is ok but rather sweet and not enough cocoa solids if you ask me. Cheesecake more than makes up for it though!
The bathrooms are a disaster. Gaps all around cubicles, loo too low, automatic flush (so you can't check what you've done, to see whether you are dehydrated or what your poo looks like...sorry if TMI but I think it's important!), and no loo seat covers so there are probably particles of dirty loo water all over the cubicle. Bleurgh!
Sandwiches are ridiculous. Especially when they're deli sandwiches. More than once, I've stood in line, stumped as there is just soooo much choice! More than once, I've asked for ham, tomato and lettuce, and been met with a puzzled stare by the person preparing the sandwich... "which type of bread would you like?" "what kind of ham?", "which type of lettuce?", "anything else?", followed up with "would you like chips with that?". And they smile while they're doing it...and it's cheaper than a soggy sandwich in London!
Medication being advertised. Medicated food NOT being advertised (unless you look closely at the label...milk with added Vitamin D, x, y and z, homogenized, etc. Humungous fruits and veg which seem incredible until you realize they are GMO and taste like flavoured water. Fat free everything, right next to the jumbo pack of Oreos.
Homeless people all over in certain cities, with tent cities on the grass verges next to city highways. Massive drug, alcohol and mental illness problems. Then they go and legalize cannabis in 2 states. 
Then you get the little gems...fluffy pancakes from heaven, rent control in some big cities, social housing in many others, amazing philanthropy (okay they get tax breaks, but it's still giving money away), more racial diversity than in Europe (ok only in some places).
Just a very different place, but I always expect it not to be. Sorry that was muuuch longer than intended.