I
highly recommend watching both seasons of American Horror Story to anyone who is interested. They are so different from each other that deciding not to watch one based on the other is, for lack of a better way to put this, a stupid decision.
Personally, I lost interest in season one after about eight or nine episodes, but I stuck it out through the end. I also thought they could have done more with Connie Britton. She's so fucking great, but in that season, she was just "good." I blame that on the writing.
Season 2 (Asylum) was
phenomenal though, aside from the (light spoiler)
subplot. I could have done without that.
The only connection is that the cast cycles in and out in varying capacities. Sarah Paulson, for example, has a tiny role in Season 1 but is a lead in Season 2. Denis O'Hare and Taissa Farmiga are in Season 1 but not Season 2; they will be returning, however, for Season 3.
And the upcoming Season 3 has so many new,
AMAZING cast members: Kathy Bates, Angela Bassett, Patti LuPone, Emma Roberts (meh tbh, but some people love her), Gabourey Sidibe, Christine Ebersole, Mare Winningham... I'll stan Coven just because of who's in it, regardless of how terrible it could (but won't) be.