If you have not seen this episode of Cosmos, this one - Episode Seven - has a great deal of good material that is supportive of the general Epicurean position and very critical of Pythagorean and Platonic idealism. It has been a long time since I watched it and if someone watches it again it would be good if we could make note of some time stamps in the thread below. I seem to remember that Sagan talks approvingly of Democritus but may largely skip over Epicurus, but this is from distant memory.
What i did take the time to verify as that at about the 39:00 Minute mark Sagan begins to take Plato apart. However if you have the time I suggest you start watching more like the 20 minute mark, where he really begins to focus on Greece: