I don't really think TCS has any filler-tracks like some people say.
I'll admit that Red is my least favorite by quite a bit (though still very good), apart from that there are only a few songs here and there that aren't AS great as the rest, but they are still very good.
"The Dead Don't Starve" is probably my least favorite song on the whole thing, not that it's bad, but the chorus get's repeated too many times.