I must say that most TV series (even the best ones) are not very re-watchable. I can see a few reruns of each episode. But, after a point, I've "been there, done that" and can't really see the same episode over and over again.

One of the few exceptions to the rule has been The West Wing. The writing on that show is superb. I have seen each episode many times, and can always watch another when it comes on the TV. One thing that kinda bugs me, though. Noone on the show ever says "YES!" to a query. When a character answers in the affirmative, they almost always casually say "yeah." Not, a solid "yes."