Happy Birthday, Sigourney Weaver: Her Most Memorable Roles

The tough-as-nails Ripley was a breakout role for Weaver, who recently revisited the character for a new Alien video game.

Though Weaver's character, Dr. Grace Augustine, died at the end of 2009's Avatar, the actress will come back as a different character in the upcoming sequels.

In 1999's meta comedy Galaxy Quest, Weaver played actress Gwen DeMarco, who in turn played the not-so-bright Lt. Tawny Madison.

As Dana Barrett in the Ghostbusters movies, Weaver knew who to call when paranormal forces set their sights on her apartment.

Weaver brought the true story of renowned primatologist Dian Fossey, who was mysteriously murdered in 1985, to the big screen in 1988's Gorillas in the Mist.

As Katharine Parker, Weaver was the nightmare boss to Melanie Griffith's Tess McGill in 1988's Working Girl.

You wouldn't want to cross Warden Walker, the cruel authority figure in 2003's Holes who made nail polish with rattlesnake venom.