Also House of Cards, the last two seasons were a little lackluster and haven't heard good things about the recent one so I'm dropping it. The real life American political system feels like a reality tv show anyway, no need for the fictional version anymore.
I enjoyed S1 to S4 a lot, but the last one was really ... meh. Will stick to it though, I think I never really stopped watching a TV show. Just taking a break sometimes, I recently continued watching Dexter after like 3 years or something...
There have been quite a few. These include Masters of Sex,The Americans, Beauty and the Beast, Ressurection, Flashforward. Also a few Australian reality shows such as My Kitchen Rules and House Rules. All of them became boring to me.
I can think about Fringe, which I watched about 6-8 episodes from the 1st season, didn't like and quit.
Recently: Scream, The Shadow Hunters and Santa Clarita Diet, watched only 1 episode via Netflix of all those series and quit.
I'm still somehow watching TWD and FTWD, I'm always thinking about quitting, because its pretty much the same predictable crap. I'm only watching for entertainment purposes, not giving much attention.
PS If you make a similar thread asking "TV series you always thought about watching, but never tried" I'd say Penny Dreadful, for some reason I never watched an episode, but always think about starting.
You should definitely watch it. Its amazing and the series has only 27 episodes so its easy to complete.