a song you wish you wrote
The first song I felt this way about was Crazy as sung by Patsy Cline (I was very little, and hadn't yet learned that my voice wasn't good enough).
The next was Something - while John and Paul seemed to be able to knock out songs, George's always seemed to come from his soul. I think everybody past puberty wished they could have said this as well as he did.
More recently, Memories of Us by Keith Urban - I would have loved to have been creative enough to sing this to my wife on our wedding day.