I wouldn't say I have a "favorite series", but there's a few I actually bothered turning my TV on for,
Stargate: SG1, I didn't like Atlantis
The Pretender
Knight Rider
Fringe
The Americans
Unsere Mütter, unsere Väter
House of Cards (The 1990 british version) and then later, naturally, the netflix one
Star Trek: Enterprise, the one bashed by all the hardcore nerds
Homeland
The West Wing