Oh snap, TOM HANKS AND BRYAN CRANSTON FOR SEASON 2, COME ON PEOPLE WE ARE THROUGH THE LOOKING GLASS HERE.
The issue I have with Tom Hanks is he doesn't inspire dark and depressing past of the season 1 protagonist. HBO would have to get Michael Fassbender or ... Liam Neeson to live up to the casting of McConaughey. Bryan Cranston is a good choice. HBO can afford him.
Also Robert DeNiro, if he actually want to act again.
edit: wait they need US actors for the series right? Never mind my first 2 suggestion.