Ah, BBC America sounds pretty awful.
British TV is FANTASTIC when it comes to fact-based stuff, like regular News, in-depth documentaries etc...but when it comes to drama, it sucks.
Well, that's not quite right. British TV is generally all 'good'. Which means there's rarely any *excellent* stuff, and rarely any *awful* stuff. But it also results in it being very, very dull.
American TV, on the other hand, from what I can tell, is able to take a few more risks, simply because there are so many channels. Therefore you get a HELLUVA lot of complete rubbish, but you also get the superb shows that the UK just can't produce (such as -at various points in time- 24, Sopranos, West Wing, ER, Farscape...).
So if you want a generally good standard of TV, always of good quality, watch British TV. If you want generally crappy TV, but with the occasional AMAZING show, watch American TV.
Of course, we actually get the best of both worlds, in that we have all the good American shows imported, but don't get any of the crap.