There are really only three Anime that should be considered IMO. Ghost in the Shell I think stands toe to toe with any sci fi in book or video. Neon Genesis Evangelion as a groundbreaking point in Anime and Saikano, which may or may not be ‘sci-fi’ enough to be on the list as it’s more human interest than ‘pure’ sci fi.
I don't normally watch Anime but Evangelion was good.