If you really want to delve into the Beatles, you need to get the bootleg masters as well. They have most of the earlier takes on them, like Take #1 of Help... (the guitar sounds horrible and it's just an instrumental)
Alternatate versions of some of the songs like 'Lucy' and slower versions of other songs. There's also a ton of them just leaving the tape running while they're talking about things...
ie, like in Help for instance, it stops in the middle of one of the takes and John Lennon shouts.. "STOP STOP STOP... string broke"
Little arguments and discussions about things.
There's a couple of versions of Hard Days Night where they can't get the words right and keep singing them in the wrong order.

I think the most fascinating this about the recordings though, are that they're straight out of the mixing board. There's no sweeting been done. No added reverb. Plus you can get an idea of how they utilized the four track by listening to the various takes. They'd start with an instrumental, then do a 'reduction mix' where they would bounce tracks down to free up tracks for vocals or more guitar. Last would be the vocal tracks.
Then you can hear the difference between what it sounds like before and after mixing and mastering.

If you couple it with the book that was written years ago about the recording session info, listing the days on which everything was done and track records... you can get a pretty good idea of how the band worked together.