'Coupling' was post Friends, IIRC. Almost sure of that. I thought it was far too derivative.
There are a few shows that are doing the rounds now that you might look out for. 'Extras' is by Ricky Gervais and is superb. Very different to 'The Office' but the same.
Look out for 'The Mighty Boosh'. It would never have been made by a commercial TV company - it isn't to everyone's taste, but has developed a huge internet following.
The BBC also does great factual programs. Michael Palin's various travels? BBC. Blue Planet with Richard Attenborough? BBC. Sir Richard has also just completed Planet Earth, a program that basically chronicled some of the most extreme - and beautiful - places on the planet. The photography is breathtaking.
In America, corporate media avoids risk taking, unless they are pretty damned sure they can mitigate it and see some sort of bottom line at the end. That's how the commercial world operates and that's fine. The BBC's stakeholders are the public principally, and it has a public service charter. Within that remit it can be very creative and back projects that on paper look shaky, but turn out to be huge successes. The Office was one such example.
I do like some of the big American series. The comedy is pretty poor however; apart from 'Seinfeld' and 'Curb Your Enthusiasm' for some reason, which are excellent. Maybe it's the HBO connection since 'Band of Brothers' was excellent too. Generally, it is formulaic, tired and the series are just too long. Six well written, crafted episodes are much better than 24 mediocre ones. An episode of Fawlty Towers took on average 4 months to write.
As for American drama series, 'Lost' was good for about 12 episodes, then it just dragged, and the series finale was piss poor. 'Invasion' seems to be holding my attention more.
SOB - the BBC model could never just be suddenly adopted in the States, I agree. But living in the UK, I'm fortunate to have the best of both worlds. The BBC and my satellite commercial service with a gazzillion channels. The two aren't mutually exclusive.
It's strange, however, that with all that choice, the only things I generally watch are the BBC, or repeats of BBC programs like Blackadder etc and premium sport channels.

And the occasional History channel type thing.