Linus, for his theological acumen and his friendship with Charlie Brown. (Although he did have a moment of extreme inhumanity, when he talked the others into canceling a banquet for Charlie Brown to avoid appearing hypocritical.)
Snoopy for his coolness. He was always a little stand-offish from “That round-headed kid” for many years, then became more friendly and devoted to him near the end of the strip.
Chuck himself, of course. Snoopy is who we would like to be, Charlie Brown is who we are.
Don’t forget the lesser-known characters - Sherman, 5, Olaf, the always unseen but felt Joe Shlabotnik, and a character of whose existence many Peanuts fans are unaware - Charlotte Braun (a loud-mouthed female version of Charlie Brown who was so disliked by the readers that she never appeared in any of the Peanuts collections, only the original strip.)