I'm surprised Truckin' isn't their most popular song though, I thought it was their most popular song for years because it's the one my mother plays the most. My favorite song by them is Friend of the Devil (and that's actually their most popular song I think XD).
The first two lines of the chorus:
'You can never be strong,
You can only be free' Sums up everything great about Robert Pollard's songwriting. Drama, hope and disappointment.