Okay, the US vs UK English one has just about been done to death...
...but let me throw one more in.

Browsing teh web to find a paper, I came across some archive/newsstand-type site. Nice little feature on the side - if you want the page translated into, say French, you click the French flag icon.
German, you click the little German flag icon.
English, you click the...

...American flag? Oh, fuck off. Seriously. Why not go the whole hog and link to the Dutch translation with a Belgian flag, or the French translation with a Canadian one? I could even have tolerated US spellings - just - but claiming ownership over another country's language is just plain fucking rude.
(LongJohnBaldry, Fri 2 May 2008, 14:49, 1 reply)

Two words...
American English.

That gets me EVERY time...
( snee held his breath since, Wed 7 May 2008, 13:15, closed)