Peter: pretty gullible, I'd say. Of course, Hiro might actually be able to convince him of something as a fellow time-traveller who he already knows.

And I see about half of Chuck on a regular basis, but it's up against How I Met Your Mother in the first half hour, so it's going to lose until reruns start. Only the existence of the pseudo-Tivo is making TV watching with a one-year-old possible at all, and it's dedicated to time-shifting my favorite shows. :)