Inspired by Film School Rejects, here are my choices for the best onscreen butt-kicking fights or showdowns loosely defined here to suit my purposes :

1. The Bride (Uma Thurman) vs. Vernita Green (Viveca Fox) in Kill Bill, Vol. 1 - This fight scene set the tone for the whole series. It was raw, gritty and a little disturbing.

2. Ripley (Sigourney Weaver) vs. the Alien in Aliens - Ripley so kicked some alien butt in this flick although the whole mystique may have been ruined by the sequels that followed.

3. Gavin Banek (Ben Affleck) vs. Doyle Gipson (Samuel L. Jackson) in Changing Lanes - They didn’t quite battle with their fists but they did engage in psychological warfare with each other and their circumstances.

4. Neo (Keanu Reeves) vs. Agent Smith (Hugo Weaving) in Matrix - This is just too cool for words.

5. Boromir (Sean Bean) vs. Uruk-Hai in Fellowship of the Rings (LOTR) - What makes Boromir’s fight stand above the rest in this series was his final quest for redemption.

6. Barbara Rose (Kathleen Turner) vs. Oliver Rose (Michael Douglas) in War of the Roses - Their battle was so mean-spirited, cruel, and utterly relentless it will scare ya off marriage.

These are just the immediate battles that come to mind. I’m sure there are tons more. Feel free to share yours…