What are some great advertisements?

Answer by Yash Dalmia:

This was an initiative by students of IIT Bombay on April Fool's Day this year.
The video depicts a '100 note lying on the roadside while a student with a camera discreetly films from a little distance away.

When one of the passersby happens to see the note, they pick it up.

 On opening the `100 note, however, they see the simple message: “It takes equal effort to pick up a piece of garbage. #PickItUp."

Well played, IIT Bombay, well played.

Here's the link to the video –
https://www.youtube.com/watch?v=hM8fM43Bej0

What are some great advertisements?