Open Culture -- what more can I say about that site? -- has dug up some Allan Bloom videos on YouTube. Bloom's The Closing of the American Mind was one of the books that most influenced my thinking on education. I've changed quite a bit in how I look at education (and the world, for that matter), but it's still something that made me who I am.
Bloom forced me to look at Plato's work and take it seriously. I'd read Plato as an undergraduate and again in grad school, but it all seemed so remote and useless. I remember pouring over his translation and commentary on the Republic for hours. I finally understood why Plato mattered. He opened up an entire world of philosophy to me. I'd studied it before, but he truly brought it to life.