Definitely the crows talk has been my favorite.

A quick summary if you are not convinced. This guy has trained crows to interact with a vending machine. I am surprised by how intelligent they are. Go watch it!

I was so inspired by Joshua Klein's talk that i even sent him a congratulatory mail too. Now whenever i look at crows, i observe them, before i just used to think they were nuisance.

That talk was absolutely amazing. It was incredibly inspiring.