Lucy Liu kills about 500 people by spin-kicking, stabbing, machine-gunning and rocket-launchering in Ballistick: Ecks Vs. Sever. But the movie's most ridiculous kill is when she gives the villain a heart attack with cartoon nanobots.
In Ballistic: Ecks Vs. Sever, which has the most appropriately nonsensical title of any movie I've ever seen, there's some deadly nanotech, and the bad guy has implanted it into his infant son. But Lucy Liu is not only a kung-fu master, she's also a nanotech genius, and she gets it out of the kid and uses it on the bad guy in the end. This movie plays like a horrendous video game film, except that it's not even based on a video game. It's hard to believe they invented this from scratch. Here's Lucy studying the nanotech: