Before They Were Stars: Sigourney Weaver in a Pepsi Commercial

One of the neatest things about Sigourney Weaver being the sole survivor in the original Alien is that the actress was a complete unknown at the time, so I doubt many people were expecting her to come out on top at the end. Seriously, before Alien, her acting credits consisted of a six-second role in Annie Hall and this 1978 Pepsi commercial, where Sigourney pops up on screen for a few brief seconds at the 0:22 mark.