These have probably been mentioned already but "The Wire" is awesome, I put it above breaking bad, and just below GoT in my personal entertainment ranking imaginary system. Really... It's just freaking great. Do yourself a favor and watch it.
Other good ones: "The Killing" and "Orange is the new black" are both netflix originals (exclusive?) which I found pretty entertaining. (I just started watching The Killing season 3 for the second time.
Band of Brothers is a great series... Wish they had more than one season, maybe alternate stories following other vets... (last chance while they are still alive)
"The Walking dead" is kind of love/hate for me. It's entertaining but at the same time I wish there was more zombie scenes and less scenes of human drama... sometimes it feels like a soap opera with zombies on the side.
"The League" I loved... found it pretty damn hilarious and all the actors are great and synch well with eachother. If you want something funny, I'd put it up there with "Always Sunny in Philadelphia" another great comedy show...
I could think of more, but those are the good ones off the top of my head.