Check out the wave-particle duality as presented by Colm Kelleher and animated by Nelson Diaz for TEDEd; it's a clever explanation to a longtime quantum conundrum. Even better: it's delivered with a lilting Irish accent — which makes the historical bit about the eye-horses that much more entertaining.
If you're a fan of lucid explanations of tricky scientific concepts, it's hard to go wrong with theoretical physicist Brian Cox. But when you mix in physicist Jim Al-Khalili and Simon Pegg, you've got yourself a recipe for pedagogic gold. Also: thinly veiled sex jokes.