It's always good to hear other peoples musical choices. You may not always agree, but that's not really the point. For instance, as much as I love Bob Dylan - just look at my name - I've never thought of him as a "song" writer. He's rock n' roll's greatest lyricist, but his name doesn't come to mind when I think of someone who wrote great tunes. Something with a melody. Go play the melody of one of his songs on an instrument and see.
My vote for the all-time #1 best songwriter in popular music is William "Smokey" Robinson. Honorable mentions to (in no particular order) Ray Davies, Monk, Willie Dixon, Gershwins, Robbie Robertson, Willie Nelson, Joni Mitchell, Ellington/Strayhorn, Robert Johnson, Rodgers/Hart, Chuck Berry, Kurt Weill, Carol King and the Beatles.
My vote for the all-time #1 best songwriter in popular music is William "Smokey" Robinson. Honorable mentions to (in no particular order) Ray Davies, Monk, Willie Dixon, Gershwins, Robbie Robertson, Willie Nelson, Joni Mitchell, Ellington/Strayhorn, Robert Johnson, Rodgers/Hart, Chuck Berry, Kurt Weill, Carol King and the Beatles.