Its easy to scope out actors like Nathan because he's not one for facial aesthetics. The same goes for Ron Glass, Adam Baldwin, and Alan Tudyk. The opposite can be said for Sean Maher and possibly Summer Glau, though (he looked completely different in the behind-the-scenes interview, muchless in another show/film, and I haven't pinpointed him anywhere else).
Have you seen Tucker and Dale vs. Evil? It's pretty funny, and it's the only time I've ever liked a graphic thriller.