Greatest songwriting partnership (With a catch)?

Question

Now for the spirit of originality even if dealing with an unoriginal question like this, the following are not allowed to be your answer:

John Lennon/Paul McCartney

Mick Jagger/Keith Richards

I know it's mean, but it makes it more than just an easy 2 points.

Answer 1

Paul Simon/Art Garfunkel, hands down.  Few others can reach into your soul like they do.

Answer 2

Elton John and Bernie Taupin, with a catch, mostly just the old stuff!