The Beatles: Complete Scores (Transcribed Score)

An amazing effort went into transcribing these songs note-for-note. While we can never know exactly how each note and chord was played during the recording sessions, this behemoth of a songbook comes as close as we'll ever get, and is light years ahead of all those awful, awful "Piano-Guitar Chords-Vocals" songbooks to which we've become accustomed.
The thoroughness and accuracy of the musical information presented here is priceless.