Wow, interesting topic and some good nominees!
I will echo a few: ripley (in aliens 1&2), princes leia is an all time great and especially so in the original sw. i also was going to nominate trinity (td beat me to it) and furiosa (scotsman got that one).
I have another one that im supprised no one mentioned: “the bride” aka Beatrix Kiddo, uma Thurman in kill bill. She absolutely rocked both movies, fought anyone who stood in her way and was reunited with her daughter. She was simply incredible.
another one: Michelle Yeoh who played Shu Lien in “crouching tiger, hidden dragon”. She was PHENOMENAL! She was tough and a true bad ass the whole movie but showed incredible insight in to the mind of a troubled young lady, trying to warn her away from a seemingly glamours life that wasnt what it appeared to be. She also played a great ‘love denied’ aspect with the male lead. Just incredible.