Here it's more like Chinese and Indian akeaways/restaurants/buffets on every corner. Those two are most common, anyway - if you haven't got one of each you probably live in the middle of nowhere.
The British are very well-versed in curries and chinese food.
And Donner Kebabs...not sure exactly where they're from...
Oh, and every other restaurant chain seems to be Italian food. Not so much an 'Italian restaurant', but stuff like Bella Italia, yanno - don't really count.
We are getting more and more Japanese places, particularly in London. It's usually the more metropolitan places where you see a greater variety, obviously. Turkish, Thai, Vietnamese, Malaysian...
You often get a restaurant serving several varieties of Asian food - one near me serves Chinese, Japanese, Malaysian and Thai.
As for Mexican, not so much. The popularity of it in the US probably is just due to proximity. We have some though - some chain restaurants and some not. Durham is not a big town, but I know of at least one of each. The main Mexican chain we have is called Chiquitos but I know there are others.