Another vote for "Tomorrow Never Knows". The greatest of all Ringo grooves. The funny thing is, when I first bought "Revolver" I listened to it for over a year and ALWAYS skipped that track. Too weird for me. It didn't sound like anything I'd ever heard. Of course there's "Within You, Without You"...but it's so Georgely derivative.
I only did something similar once before. First Doors album. Took me two years to get around to "The End". And when I heard it - and I mean HEARD it- it was like "what the f...! This ain't like "Light My Fire!" That's when I learned what Mr. Mojo Risin' was all about.