Curently airing in US:
Longmire - (aussie) Robert Taylor stars as the gruff sheriff-of-few-words in a fictional Wyoming county. Simple. But enjoyable. Plus it's got Starbuck in it (the female one). And Lou Diamond Phillips from Young Guns and other movies not Young Guns.
Suits- Light, maybe slightly trashy, but really easy to watch (perhaps thanks to Megan Markle and Sarah Rafferty). Great characters, esp. the morally ambiguous Harvey Spector. Oh and it's got Zoe from Firefly. Ahhh ... Firefly.
Currently airing here:
For the love of cars - A doco-style show currently airing on one of the SBSs or ABCs (dunno since I downloaded it). I love cars, and the restorations these poms do is pretty special.
Grand Designs - Just like "The Block", only not fucking awful, and with Kevin McCloud.
Not curently airing and not Walking Dead or GOT:
House of Cards - Kevin Spacey + David Fincher. Enough said.
Veep - Hilarous. Worth watching just for character Ben Cafferty's insults.
Person of Interest - nothing hugely special, but enjoyable. Love the Shaw character ... she badass.
Motive - worth noting for being the only cop drama that isn't stupidly predictable and where you're not yelling at the screen "It's that guy who dunnit ya dumbarse!" .... primarily since the show opens by revealing the victim and murderer 'Columbo' style, and the show is about the cops figuring out who and the viewer figuring out why. Plus it's shot in Vancouver area, so I'm frequently seeing the North Shore (and sometimes Squamish) and remembering how awesome it is.
Archer - agree with above: best animated TV show ever
Castle - because Nathan Fillion (Captain Mal .... Firefly. Ahhh Firefly). But annoyingly predictable (see previous comment).
Newsroom - I loved "The West Wing" and its long, dialog heavy tracking shots. Newsroom is a newer version of this. Set in a newsroom.
Continuum - The time travel stuff appeals to me, as does the Vancouver setting. But the lead chick is so wooden I only watch it these days to see if she actually gets better.
No longer airing, but worth re-watching:
Firefly
The Wire
The West Wing