Okay, so your examples of unfunny/unintelligent American humor are Two and a Half Men and The Big Bang Theory, two shows openly acknowledged as two of the worst shows on TV, in the same genre, by the same creator, on the same network, that often run back to back. Yep. Nothing wrong with that assertion. By the way, the British version of The Office was fucking awful. At least the American version took four seasons (okay, three and a half) to become fucking awful. I also noticed you cited Family Guy as sometimes being funny. Actually, it's never funny. Ever. It's dry and lifeless when the Seth Macfarlane isn't using it as his personal "Atheism and Liberalism are awesome and anyone who disagrees is a moron because of my petty insults and utterly unsubstantiated claims" soapbox and grating and idiotic when he is. See? I can present my opinions as fact too. That doesn't mean they are, and that doesn't give you the right to insult anyone who disagrees with you. Sure, you guys have some funny stuff now and then, like Hot Fuzz, Monty Python, or anything involving David Mitchell, but most of it is crap. Just like ours. Seriously, this would be like me reading Twilight and saying that the entire Gothic Fiction genre is crap, completely ignoring anything by H.P. Lovecraft or Edgar Allan Poe, then presenting that ridiculous assertion as fact.
And as everyone else has stated, South Park is 100% American.