Name some songs over thirty years old that don't sound at all dated (i.e., "evergreens").

One example is Pretty Ballerina recorded in 1967 by The Left Banke (click on link to listen). Another example, of course, is God Only Knows.

straight out of my previous s10 from 71:

Hiro Yanagida's "Yūutsu": filters the Velvet effectively out of the Underground and precedes the likes of Stereolab or Yo La Tengo

Hate to go with such an easy choice, but...

I had never heard the Beatles' "Tomorrow Never Knows" until a couple of months ago (go ahead, call me sheltered...) and it sounded like something that could have been released any time in the last decade and still sounded fresh.

Not quite 30 years old yet, but I would never have guessed the first time I heard Prince's "Kiss" that it was made in 1996. Still sounds like it could have been made yesterday.

*1986. Whoops.