A robot may not harm humanity, or, by inaction, allow humanity to come to harm.

- R Daneel Olivaw

The Three Laws are:

1. A Robot may not injure a human being or, through inaction, allow a human being come to harm.

2. A Robot must obey the orders given to it by human beings, except where such orders would conflict with the First Law.

3. A Robot must protect its own existance as long as such protection does not conflict with the First or Second Laws. 

MB #93 Robotics

One of the newest and one of the coolest MB's. While I did not build anything like this...

I did get to use some Lego Mindstorms and build something like this...