In my opinion, Rubber Soul is the single most important album of the Beatles era (I was 15 at the time it was realeased). It was the very first album ever with a theme and not just a collection of songs.
Even today, I still enjoy listening to it on CD and my two teenagers love it too and are amazed at the musical diversity of the various tracks.
Three of those 4 albums were released in 1965. Man, talk about a great couple years for music.