Attack on Titan is whiny and lazy garbage for the first two seasons. Nothing happens, the main characters are flat as a piece of paper, and the secondary ones are forgettable and are way too many. Season 3 is where it gets marginally better.
American Dad is the worst animated series ever conceived my mankind. I am seriously appalled and shocked that anyone could like it at all.
Harry Potter is good, but predictable and at times even boring.
Tarantino is not gifted with synthesis and his 3-hour-long movies heavily suffer for this.