If I had to rank the seasons, I'd say:
1st - Murder House. Scary, dramatic, sexy, and fun. Dylan McDermott was so hot. I also liked Teddy Sears. Jessica's portrayal of Constance was fantastic and definitely deserving of her Emmy. Lily Rabe was absolutely gorgeous.
2nd - Hotel. All of the elements that Murder House had, plus it was very stylish. I liked the vampire angle. Evan Peters' best season and best acting.
3rd - Freak Show. Dandy, Scary Clown, Madame Elsa, Ma Petite, and all the other memorable characters. I loved the music from that season, and by far it was the most star-studded cast of all: Jessica, Kathy Bates, Frances Conroy, Angela Bassett, Michael Chiklis, Wes Bentley, Matt Bomer, Gabourey Sidibe, Danny Huston, Neil Patrick Harris, Malcolm Jamal-Warner, Chrissy Metz, Lee Tergesen, Patti LaBelle, Mare Winning ham, David Burtka, plus the regular cast of AHS. That's pretty damned amazing.
4th - Coven. Very strong writing, until the zombies showed up. Myrtle Snow was one of my favorite characters of all seasons.
5th - Asylum. Started out strong and scary, but the alien element ruined it for me.
6th - Double Feature (First Half). Those vampires were scary and creepy as hell. I also loved the campy element of Evan Peters and Frances Conroy singing karaoke in the local bar. The Second Half of Double Feature sucked. The two gay guys were cute, though.
7th - Apocalypse. It was very different from the other seasons, but I liked that they brought back a lot of past characters, and connected Murder House to this season.
8th - NYC. The serial killer was by far, the creepiest part of the season. The acting was great, and the story was strong. It probably should be ranked higher, but I just happen to feel a lot of nostalgia for the earlier seasons.
As for the rest, I thought they weren't very good. I got bored with 1984 halfway through, and Roanoke was just horrible. The acting: UGH! I honestly don't remember too much about Cult. I'm not sure why, but if I can't remember it, then it must not be that good. And I didn't even bother watching Delicate, because I cannot stand any of the Kardashians.