I think the lyrics to "Yesterday" are perfect. They are deceptively simple. They express a timeless sentiment in a few words, no more complicated or ornate than is needed, and perfectly wedded to the melody and meter of the song.   The tight rhymes don't smack you in the face because the statements are natural and not the least bit contrived.

It's not every day you find a song so expertly crafted.


I also think McCartney's lyrics to "When I'm Sixty-Four" are pretty nifty.