Not the biggest Beatles fan, but I find the recent colourized tour videos fascinating. There's the ones from the Munich circus show, on US TV, at Shea Stadium (where they barely could hear their own playing because of how loud the crowd was), or this one:
You notice how tight they were live, and that it sounded just as good as the record, if not better.
And McCartney's and Lennon's harmonies were insanely good.