I enjoy the British and American english differences and it generally makes any trip to Great Britain a very culturally rewarding experience. Some of my favorite variations:

Toilet vs. Loo
Bonnet vs. Hood
Vacation vs. Holiday
Apartment vs. Flat

I think my favorite British english term is 'Yob', which I take to mean any of the following: Jerk, Drunkard, Idiot, Buffoon, Clown...

In any case, yob always brings a smile to my face.