Actually, by British standards America appears an irony and sarcasm free zone. Not that this is necessarily a bad thing, but it is very noticeable.
update: searched a bit, cannot find any supporting evidence for bioh42_2's statement.
Not always intended as sarcastic, but:
The main body of the news report tends to use the renarrative correctly - but sometimes, again, it is intentionally avoided. (...) This is because, due to its ambiguity, the renarrative in such cases could be perceived as a passing of judgement or expression of doubt by the reporter...
You could say that something like "Seinfeld" (and "Curb Your Enthusiasm") is more the product of a very unusual subculture (in fact, this is the basis for much of the humor, how poorly new yorkers fit in the rest of US culture), but keep in mind Seinfeld had the highest ratings of any sitcom in US history, so the appeal is obviously very broad.
Incidentally, I wouldn't regard Monty Python as being very representative of "natural" British humor - I'd probably suggest Al Murray in his "Pub Landlord" persona to be far more like the comedy you are likely to encounter in real life (or Frankie Boyle for us Scots).
FWIW, I think both versions have their charms.
Most of the sarcastic comments, the tone and the nature of sarcasm does not even parse for a westerner.
In fact you will see a lot of Indian language sarcasm directly "translated" to English leading to hilarious situations.
British just came, looted and left. It would be good if people stopped attributing every god-damned thing about India to the "British Influence".
My bad. I just wondered, considering that British humour is a lot dryer than American humour. I apologize if my comment was misconstrued in anyway.
At the height of British occupation , there were not more than 1700(!) British people at the same time on the Indian subcontinent. Which itself is a fantastic testament to the British Raj's bureaucratic machinery. The English education was an instrument in creating that machinery.
What is very valuable is to describe them in terms of how they are different from your culture.
Thus compared to Asia they are very sarcastic, and compared to Britain hardly at all.