Favorites for me... that's tough (most of my favorites have either completed their run, or are long off the air). Currently I am trying to follow:
Agents of S.H.I.E.L.D. (I am really enjoying it more than I though I would)
Agent Carter ( really like this one... for many reasons not just it's context)
Elementary (though I am starting to lose some of my interest, I do like the way Sherlock is portrayed in it)
The 100 (Did not have high hopes, but I am pleasantly surprised overall)
If I had cable, and when I get chances to see them:
Game of Thrones
Doctor Who (and I miss when it was on PBS as a child)
There are a number of shows I try to follow, and initially liked or had hopes for, but have started or continued in trends that are very irritating to me. These include Supergirl and Flash. I initially really liked the Flash, but I hate that more and more people know his Identity, and that he needs a support team to help him (hated this about Arrow and so never got into it despite loving the comics). I have the same issue with Supergirl (the secret identity issues) but also dislike that somehow they have managed to take the strongest woman on Earth and make her seem more fragile and weak then a certain Agent (I love how Agent Carter comes off as strong willed, not just strong in a fight or skilled combatant, but conversely it seems the writers of Supergirl are too obsessed with making her seem less capable, full of self doubt, awkward, and overlaying heavy layers of "Girl Power" messages relayed through her mentor...which just sort of irritates me... make her a good, strong, rounded character and the message would be self evident in my opinion).
There are other shows I try following when given the chance (Manhatten, Turn, the Strain, Dominion) but I always find the need to keep my mind distracted from itself, lest my depression overwhelm me.