To be fair, British Television, full stop, has an advantage due to the mere existence of Charlie Brooker. British game shows are boring, American Games shows are stupid. British Reality TV is just like American reality TV, only 1 year ahead of schedule. News programs are on about the same level, so no reason to compare. Newer children's programming in the US is cheap, and usually done in Adobe Flash to save time (save for a handful of shows that actually care about what they're teaching kids). Britain, on the other hand, can put out shows that are annoying as all hell. Please, go back to stop motion. Knock it off with all the guys in bulky costumes dancing around in front of green screens.
Back to sitcoms, though.
Overall, I think the American sitcoms, past the 90's, are basically like mild flavored.
Bland, stupid, humor. Easy to digest stories that don't take many risks, and only seem to offend thinking people.
When you get right down to it, Family Guy is one of these shows.
It does nothing to challenge it's target audience, and makes sure that it's references connect with said group. The jokes are very simple, any idiot could understand them, and the political humor is about as subtle as a newspaper comic. But, since it's sound investment, fox will push this show to the moon. And that's, generally, the state of comedy in the world today.