I've been living in the USA for six and a half years now, and I'm used to much of it. I'd have trouble driving on the left, for instance. There are some things that still get to me, though. Here are some of them.
Bread. American bread falls into two categories: sourdough, or sickly sweet. Americans don't notice this, but it really annoys me. I'd kill for a decent crusty white from England, and would go as far as a solid slap to the face for Hovis. It's that bad.
Urinals. Specifically, the need to flush the damn things. I grew up with timed flush and the occasional infrared sensor flush in swanky buildings; I just don't have the reflex to flush urinals.
Toilets in general, in fact. You'd think a country with large tracts of desert would see that it might not be the greatest idea ever to have a gallon or so of water in the toilet bowl. You only need enough to form a seal and keep the sewer fumes from infiltrating. As for the insistence on flap-valve flush mechanisms, I can't fathom it. There seems to be a pervasive air of thought that it only has to work long enough for the repair bod to get back in the van, and despite universal metered water, it's fine if it fails open. The concept of a flush mechanism that's leak-proof, nearly failure-immune, cheaper to repair when it does fail, and makes the flush more powerful, well... try explaining it to them and they'll look at you like you've grown three heads. The idea of "something other people do better at" is beyond them.
Politics in general is irredeemably toxic. Too much money, not enough accountability.
I found it much easier to not give two hoots about religion when I lived in a Christian country. In this officially areligous country, there are constant efforts to institute a theocracy. I've reconsidered my youthful disestablishmentarianism...
If how much one pays is an indicator of quality, America does have the best healthcare in the world. By any other metric, I'm constantly gobsmacked at the fact that we don't have a Medicins Sans Frontiers presence.
And would it kill them to have back bacon, and maybe consider not overcooking it so much it'll take an edge? Bacon is not meant to shatter. Apparently Americans believe bacon is a kind of salty charcoal.