I watch a lot of tv series, but most of my favorites have been cancelled
Ok here goes:
The Vampire Diaries, True Blood, Teen Wolf, Supernatural, Downton Abbey, Smallville (cancelled), Arrow, Once Upon A Time, Grimm, Haven, Legend of the Seeker (cancelled), The Walking Dead, Agents of S.H.I.E.L.D., Politcal Animals (cancelled), Xena (cancelled), Hercules (cancelled), Young Hercules (cancelled), Friends (cancelled) Gilmore Girls (cancelled), Terra Nova (cancelled), White Collar, Falling Skies, Fringe (cancelled), Buffy (cancelled), Angel (cancelled), Suits, Justified, Rizzoli and Isles, Heroes (cancelled), The Big Bang Theory, How I Met Your Mother (cancelled), Witchblade (cancelled), Firefly (cancelled), Closer/Major Crimes, Alphas (cancelled), Sanctuary (cancelled), Ghost Whisperer (cancelled), Merlin (cancelled), The New Girl, Revenge, Covert Affairs, The X-Files (cancelled), Alias (cancelled), Warehouse 13, Community, The Office (cancelled), 90's X-men animated series, 90's Batman series, Moonlight (cancelled), Being Human, Dallas, That 70's Show, Kyle XY (cancelled), The River (cancelled), Cougar Town, Person of Interest, Defiance, Wolflake (cancelled), Blood Ties (cancelled).
I'm looking forward to watching Sleepy Hollow, Dracula, and Gotham.