Vi Hart makes videos about math. Funny, smart, and entertaining videos about math. My fellah is a math geek and introduced me to her, and I couldn't be more grateful. He started me off with her three videos on spirals and plants, and so now I think that's where everyone should start.
So, without any further ado, may I present, VI HART! (Wild applause, high fives, high kicks, leaps, and spins ensue.)