One addendum: The thing I enjoy the *most* from this era's lecturers, is actually not their enthusiasm (that's the second best thing about them); it's the complete and total absence of computer graphics/simulations/animations.
Using paper, cardboard, live demonstrations (the best option), and just a masterful articulation of the subject matter to convey the ideas at hand, is SO preferable to me, compared to modern teaching via computer animations and PowerPoint bullet statements with cheesy clip art. "Is this going to be on the test?" is the most frequent question asked in school today. If I attended lectures like this, I'd never leave the school.
Perhaps that's also why I love Dave's and W2AEW's videos so much. They exhibit the same quality set: effective visual aids (graph paper, whiteboard, perfect), live demonstrations like breadboards, meter readings, scope screens, etc., eloquent lecturing that is straight to the point, unambiguous in word choice, and enthusiasm for the subject, even the math!