Boston Dynamics Big Dog (new video March 2008)

It looks like an actual biological quadruped. Seeing it climb through rubble, snow, jumping over obstacles like a wild goat, and saving a near-fall on iced ground at the last second (fast forward to the middle of the video) defies belief. It feels so "animal" that I almost feel bad when they hit it to demonstrate how it regains balance on its own.

The new version of the robot can now carry 340 pounds, which is almost triple the previous weight. LINK, Via: Youtube