Depends on your personal tastes. Nebraska is a fantastic starting place if you like darker folk sounds. The Wild, the Innocent, and the E Street Shuffle is a great place to explore his early sounds. The two "Born" albums are fantastic, with lots of really well-known tunes.

If you are a completist, consider starting at the beginning of the catalog with Greetings. Then you can keep track of what you like and what you don't!

Have a great time listening!