Michael Tilson Thomas has a great music documentary series called "Keeping Score". The very first one I saw was the one on Stravinsky's Rite of Spring. Fantastic. So I was pretty excited to find that he had done one for Beethoven's Eroica Symphony in 2006. And then to my great surprise I found on Youtube that he'd done a documentary on the Eroica in the 1990's as well! He must really like this piece.
Check out the earlier documentary made with the London Symphony Orchestra below (40 min). He exaggerates some of the anecdotes a bit, but he makes up for that by playing a Steibelt (B's competitor) piece which I had never heard, and makes a fascinating case that the Steibelt incident (a piano duel) was the source of some Eroica themes:
and check out the somewhat more seasoned Tilson Thomas in Keeping Score: Beethoven's Eroica (58 min) here.
And finally have fun with the Keeping Score Eroica website which has one of those interactive animated score thingies I like so much...a fine presentation.