To borrow from Carl Sagan’s famous dictum concerning the universe, every other character on this show is a way for Chuck and Sarah to know themselves. Ellie and Awesome are the stable, functional relationship that throws the problems in how they (C&S) relate to each other in sharp relief. Jeff is the lonely guy Chuck might have become after the fallout from Stanford. Carina is a version of Sarah who chose to be a federal agent and clearly lives for it.

http://chuckthisblog.wordpress.com/2011/08/24/summertime-top-ten-chuck-versus-the-other-guy/#comment-51620