This is after watching all three seasons, the movies and also the manga.
I really enjoyed bungo stray dogs! It was an interesting start, and things were a bit slow on the uptake, but the anime progressed really well, and it's a somewhat light angsty supernatural action anime that some love. I think the thing that puts people off is how slow it progresses at the beginning, and that's why some drop it but then again I'm not really a justifiable source so ignore me.
The main reason I didn't drop the anime was because I had already seen clips and reviews of the anime beforehand... See full review
Based off memory - I really enjoyed assassination classroom. At first, it wasn't truly interesting, and the plot made me wince because it looked very cliche in some aspect, but overtime, I became attached to the characters and the plot. It was enjoyable to see how they developed, and the storyline really highlights high school and the classroom environment.
I won't leave spoilers, but I really recommend the anime!