I give up on a hell of a lot of shows before watching a full season, but as far as significant investments such as a season or more-
Downton Abbey- would like to finish
Vikings- watched too much too fast I think
House of Cards- any surprise?
Walking Dead- meh, could have been a movie
Handmaid's Tale- Would never have predicted this after the first couple
Bosch- was never that good
The Wire- not sure why. It was pretty awesome
Servant- was scaring my wife too much
Every Marvel show ever
Why didn't I give up:
Titans