Pretty much all of the good stuff is listed. Here's some hidden gems for the bored out there.
These are shows that aren't exactly mainstream but are great nonetheless.
The Wire
Archer
Jerhico (Cancelled but still a great few seasons)
Lillyhammer (Netflix)
Threads (old BBC series)
Survivors (BBC)
Luther (BBC)
Any of the Sherlock Holmes series
Any Dr Who show made before the advent of computer generated daleks. (Bleech
)
BTW speaking of Daleks, I just read that the orginial Survivors was created in the late 1970's by Terry Nation. I've never seen that one, I was referring to the 2008 show. Gotta track down that show now!