Some types of tv programmes are better done in the UK and some are better done in the US, I think. I watch (and have watched) a few US shows: CSI (NY and original); The Mentalist; House; Monk; Friends; Frasier. The UK shows I watch just now are Doctor Who, Merlin, 'intellectual' quizes (e.g. University Challenge, QI, Have I got news for you), documentaries (e.g. Horizon, Unreported World, Imagine, Bang goes the theory), sitcoms (Red Dwarf, the IT Crowd) and comedy panel/ stand up shows. There are many classic UK sitcoms, but I believe there's an old thread on here about them. I don't watch any sitcoms at all now, except for the occasional Big Bang Theory.
I sometimes get hooked on US series like Lost and Heroes. But, after a while, when we still don't have a clue how the story is going, I get bored. Quite often what happens with the these shows is that they end up on pay channels and I don't get to see the last ones, as I only have freeview, but by then I don't really care. I'm following Once Upon a Time just now and I really hope it is concluded, by the last episode in the series. This series is better than most US fantasy series I've watched, because each episode has it's own distinct story. So each episode can stand alone, but not as effectively as Doctor Who episodes. If it goes on to another series, I'll probably stop watching.
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"We act as though comfort and luxury were the chief requirements of life, when all we need to make us really happy is something to be enthusiatic about." Charles Kingsley