'The Office' (U.S.)
Everyone has an opinion about the quality of the American Office, but there's little denying that after six highly-rated seasons, things fell apart. Perhaps it was when Jim and Pam got married, zapping any sexual tension. Or maybe it was when Steve Carrell left the series for greener pastures (a.k.a. the movies). In any case, NBC should have put the kibosh on the whole thing three seasons sooner.