If you ask me, tho, runner-up would definitely be "Sloop John B". Forget about corny folk like "Kingston Trio", the Boys owned it. BIG TIME.
Agreed, Brian bettered the KT's version by plenty.
While the "folk" part is correct, I don't agree with "corny" to describe them, however. Part of their stage act did involve clowning around, but when it came time to perform, the Trio could play and sing with the best of them, and at their peak they were immensely popular. They left a body of work that compares favorably with most US groups, and have been listed as influences by many musicians, including one fellow named Jardine.