Strong Female SF Characters Beyond Ripley?

In his column for FilmCritic.com, science fiction author John Scalzi takes a thought-provoking look at female characters in science fiction films. I particularly like Scalzi's coinage of "spinny killbots" to describe the stylized super-fighter/sexybabe characters prevalent in many SF and action films. Not that I don't enjoy watching a good spinny killbot, mind you -- and nor does Scalzi -- but his point is well made. Thoughts? Any strong but non-spinny-killbot female characters to recommend?