Cyfu said:
I doubt you have seen real-Who, only neu-who. There are hundreds of hours of Who, even if you start with the colour era. You'll miss the second best companion, Jamie, if you do that though.
Everyone is going to say The Wire, and they are right.
Deadwood is also great, I'd put it right up with The Wire. Ian McShane is formidable.
Generation Kill is Band of Brothers for the current generation, and well worth it.
If you have any love for police shows, then Homicide: Life on the Streets is just behind The Wire in greatness. If nothing else you can see the birth of John Munch, and gaze in awe at the presense of Andre Braugher.