There are too many to list, Lots of active shows still being aired. As well as ones that have been finished/cancelled. Hulu and Netflix are pretty good at matching up shows/movies to your liking. I watched some series on Hulu called
http://www.hulu.com/new-amsterdam which started off really good but unfortunately it was cancelled mid season. If you like TV shows like Fringe, Supernatural, Xfiles and that type of thing heres a good list for those who haven't seen these since they mostly went unnoticed or were never renewed.
http://www.hulu.com/journeyman
http://www.hulu.com/john-doe
http://www.hulu.com/the-dresden-files
http://www.hulu.com/the-pretender
http://www.hulu.com/endgame
And there are oh so many more. I have a shit ton of free time so I always have some show running on my second monitor. I don't watch most comedys, Big Bang Theory is about as much as I watch as far as that goes and only when nothing else is on.
As far as what I am currently watching right now, Just to pull some names out of my torrent folder:
Bones
Castle
Game of Thrones
Bates Motel
Vegas
Person of Interest
Walking Dead
Lost Girl
Supernatural
The Vampire Diaries
Star Trek(TNG, DS9, Voyager)
The Shield
Vikings
Criminal Minds
House Of Lies
House of Cards
Spartacus
Banshee(good show on starz or showtime something)
The Americans
Justified
NCIS/NCIS LA
The Following
White Collar
Elementary
Hell on Wheels
Continuum
Teen Wolf
Breaking Bad
Grimm
Longmire
Secrect Circle
Falling Skies
True Blood
I could go on and on with cancelled and still airing shows but i covered some. Hopefully Defiance, We'll see this monday.