Sword Art Online
The characters were very unoriginal and lacked any personality or depth, the plot was all-over the place and had its holes and a lot of other things like Kirito being grossly overpowered. I think the biggest complaints are because of the bad characters and writing.
Tokyo Ghoul
The anime original changes didn't really fit in the story that well and many of the best parts were rushed or not even adapted at all.
Dragon Ball Z Super
The context of the characters is, by far, the most irredeemable factor of Dragon's Ball Super downfall. Generally, in an action-focused anime, main characters continuously get stronger, so villains have to as well.