First things first, Taissa Farmiga needs to come back. My ideal AHS season has to have Jessica Lange (Constance, Jude), Lily Rabe (Nora, Mary Eunice, Misty Day) , Evan Peters (Kit, Tate etc), Taissa Farmiga (Violet, Zoe), Frances Conroy (Old Moira, Death angel etc. ), Matt Bomer (Donovan) and Jaime Brewer (adelaine, nan) in it.
My favourite theories include Apocalypse, Arctic Tundra, Cult and Space.
Personally *i* think it would be totally awesome to make a season where Lily Rabe is a psycho murderer and Taissa Farmiga is her daughter who tries to stop the her from hurting her boyfriend (Evan Peters) and her dad (Denis o'Hare). Frances Conroy could play the murderers mother and Jessica Lange could play the murderers sister. Maybe even Jaime Brewer could play the murderers sisters child. i dont know ;D The location would be a family's summer house and the plot would be that the bridge that you need to cross to get there has crashed so they cant escape.