This is going quite well - thanks to those who've contributed.
I've sorted the first lot into alphabetical order (OCD) but if any additions are added above this list please so we can see new ones as they arise. I'll pop in to re-sort them every once in a while, okay?

With so many channels available these days I find it difficult to keep up with what's new. I'd find it useful to have a list of 'worthwhile' telly to watch that I may have missed.
If anyone knows of either any new series coming up or decent series [cult status?] worth digging out please list them below. Maybe a separate wiki for UK series? Perhaps if enough interest we could make it a sticky?

Additions:

Sorted list:

24
Alias
American Gothic
Band of Brothers
Battlestar Galactica
Boardwalk Empire
Breaking Bad
Continuum * SF
Copper
Damages
Deadwood
Dexter
Entourage
Firefly * SF
FlashForward * SF
Fringe * SF
Game of Thrones
Generation Kill
Hatfields & McCoys
Hell on Wheels
Heroes
Homicide: Life on the Street
Homeland
Jericho
Justified
Louie
Mad Men
Magic City
Oz
Prison Break
Revolution
Rome
Rubicon
Six Feet Under
Sons of Anarchy
Southland
Spartacus: Gods of the Arena
Spartacus: Blood & Sand
Suits
The Pacific
The Mentalist
The Wire
The Shield
The Sopranos
The Walking Dead
True Blood
Vegas
Warehouse 13 * SF