We like to josh our American cousins over the fact that they can't speak proper English, but actually I think that many of the most heinous crimes against the language take place on this side of the Atlantic.
Earlier this week a shop assistant apologised for giving me a handful of pound coins in my change because "I ain't got no fivers". I resisted pointing out that he was talking nonsense because a) life is too short and b) he was a lot bigger than me.
Here are some other common phrases that really grate when I hear them:
The only Americanisms that I can think of that come close to those are "gotten" and "math" (instead of "maths").