Supernatural: Essential watching?

My brother is coming home tonight and I have declared my intention to irrevocably addict him to Supernatural. However, I want to make sure I hook him on all the best episodes (or the ones that spell out the necessary mytharc points). I figured I'd start with the pilot and end with "Born Under a Bad Sign" due to the sheer awesomeness of the episode. But what should I put in the middle? What is essential? What is your top 5 episode list?

Any suggestions?