@tsarstepan,
I've read four of them - I haven't read the Pynchon or Faulkner - I can't read Faulkner, although I know other people who love him - he's too wordy for me - I have to read and reread his sentences and although I think his themes sound interesting and his settings are exactly my cup of tea - I've never made it through a piece of his. Pynchon is someone I've never explored.
So when you posted this a few weeks ago - I was delighted to see Flannery O'Connor and Ralph Ellison - two of my favorites - but then I hit a stalemate and couldn't vote until I reread Invisible Man - which I have and now I'm ready to vote - for Flannery O'Connor.
Invisible man is important but I think Flannery O'Connor is innovative in a way no one else is with themes that are universal.
so yeah - my vote goes to Flannery O'Connor