When Glenn was murdered with the baseball bat - the picture and him saying Ma- Mag- Ma
It was just too intense for me. I just closed the book and walked away for a long time.
When my husband saw that part in the show he just stopped watching. Also too intense for him
I watched the last episode of the season (when we see someone eating a bat but don't know who) and was like "Ok, this thing has been shit for a while, that's enough." and only watched the next episode years later to know who was the victim and that confirmed my lack of interest for whatever came after.
To add, that same season they already killed Glenn.
He dies, but the show doesn't really address it. The characters do, but the show at this point was SUPER clear when a character died. Extra slow motion, special music, the works. Then they spend like 6 episodes with him dead, but you really just don't believe it. Then they reveal how he survived and it's just ridiculous, it's basically "the zombies just sorta give up for some reason". (Or is it like a dozen headshots, I forget at this point).
Anyway, ALL that happens, then the season ends on a big cliffhanger. Unfortunately the tension is all wrong. The show was moving at a glacial pace where basically if you watched the season opener, the mid-season finale (see, above) and the finale, you'd be mostly caught up on the story. And so this finale robbed us of that too.
Also the Internet was full of spoilers saying it was Glenn (from the comics) such that all excitement was lost between seasons.