I know this is a very tough question, but if you had to pick what would it be. I am in the middle of a Beatles obsession right now. Mine would either be The Ballad of John & Yoko, Yer Blues, Rocky Raccon, I dig a Pony, Norwegian Wood, or Taxman. Maybe throw Hey Jude in there. Ah, Heck some of their Phsychedelic Rock is great too. All timeless classics I tell ya.