Hannibal!!!!!!!
-Seriously, this is the best thing on TV right now. It gets overlooked a lot since it's on NBC, but I assure you, the quality is Breaking Bad level IMO. The acting is awesome. The dialogue is usually great. Every single shot is fucking gorgeous.
Justified
-Fun, western style show with lots of great dialogue and acting. Villains of the week are fun, and the overarching plot is prevalent enough for you not to feel like the show is treading water. The show has some of the best characters and villains I've seen.
It's Always Sunny in Philadelphia
-I'm amazed that this show is still so funny even when it's about to enter its 10th season. It follows a group of terrible people and allows you to make fun of their exploits and occasional successes. If you watch one episode, watch the Nightman Cometh.
House of Cards
-Kevin Spacey is awesome, but one of the biggest surprises for me is Robin Wright who plays his wife. The performances in the show are very strong and the scheming is delightful. Robin's character is perhaps one of the best female characters I've seen on TV in recent memory.
Community
-It's been an admittedly bumpy road, but the first 3 seasons are pretty great. It has some truly unique humor and is really quite a touching show.
Arrested Development
-This is probably the funniest show I've ever seen. It has a lot of long running gags in it and as you may be able to tell from my avatar, Gob is awesome. His chicken impression is particularly spectacular.
True Detective
-An excellent thriller that offers a lot of grim contemplation. The tone of the show makes the ending's payoff particularly sweet. The show offers some of the best acting I've seen on TV as well as some really cool scenes. There's a single shot scene that goes for a good 10 minutes. It's fantastic.
The Wire
-The writing and acting are both quite good. However, the show just wasn't for me. It was, quite honestly, too depressing. I kept going "I get it, shit is corrupt, can we fix it now?!" I realize that it's taking a very real look at the world of drug dealing and it probably deserves every bit of praise it gets. I could only get through one season though.
Spartacus
-I'll admit that this is more of a guilty pleasure. However, if you stick with it, you grow quite attached to the characters and embrace the ridiculousness of the show. I thought it was excellent, despite the occasionally laughable dialogue and inconsistent acting. The visual style also takes some getting used to.
Sherlock
-The first two seasons are great. The third.... not so much. Great acting, and consistently funny dialogue. Each episode is basically a feature length film. While this format does cause a couple episodes to drag, it really lets them do great things.
Fargo
-Lorne Malvo takes this show from being just good, to great. His character steals every single scene he is in. The ending was a bit of a let down, but apart from that, the show was consistently well written, and acted, throughout. Also, the show nails the tone of the original movie.
Arrow, Agents of Shield, and Flash are all pretty good for what they're trying to accomplish. They don't really come anywhere near the others in terms of actual quality though. They're fun superhero shows that occasionally offer glimpses of truly excellent TV. My current favourite is the Flash, but they're all pretty equal IMO.
There are some series missing from here that are considered pretty great, chances are, I just haven't gotten to them yet.