Season one was great, it gave the extreme horror-esc kind of vibe. It had great dialogue, characters, and interaction. I found season two to be less scary than season one. It dove into some more serious topics like child safety, sexual abuse, psychosis, and more. But it felt more open-world like there wasn't a necessarily chilling atmosphere that made it suspenseful. Season two expanded the cast, and though it was slower-paced than season one, I still found it extremely entertaining with some more interesting characters than the last.
Season three is again, in a way a mix of the other two. It keeps most of its formulaic routes but does things differently. (Like keeping the main love interest for two seasons). For most people, season four is either their favorite, or least favorite season. It depends on the type of viewer you are.
All in all, this show is extremely intriguing, suspenseful, and different from the rest. It gives us the worldview of a non-remorseful sociopathic killer, and it's an extremely interesting ride. I think this show has everything. It's dark, but not too dark. And just when you think our main character is finally changing, he pulls the switch and reverts to psychotic ways of thinking. This show is easily a 5/5. Here's my ranking of each season-worst to best...
4. Season 3 - (7/10)
3. Season 4 - (8/10)
2. Season 2 - (9.5/10)
1. Season 1 - (9.5/10)