John Lennon vs. Paul McCartney
True, they were technically on the same side, but even during their years as fellow Beatles, the creative competition between Lennon and McCartney spurred two of pop music’s most prolific songwriters to stretch their abilities and redefine rock ‘n roll on a regular basis.
As McCartney explained, their individual songwriting processes frequently involved an unspoken conversation. Lennon would bring in a new song to the studio, and McCartney would head home to try and do something similar, but better.
And people wonder why solo John and Paul were so much worse.