Superman: Matt Keeslar would be the best Superman ever. Just watch The Middleman
Lois: Gina Holden. Her Dale Arden in SciFi's Flash Gordon
was very Lois-like, and she's more gorgeous than just about any screen Lois except Kate Bosworth, who was incredible to look at but totally wrong for the part.
Luthor: Several possibilities. Clancy Brown with a shaved head; Sherman Howard (who did a terrific Luthor in the '80s syndicated Superboy
); Michael Rosenbaum 15 years from now.
Jimmy: Michael Landes from Lois and Clark
, but maybe a few years younger than he was then.
Perry: Hmm... how about Chi McBride?