I've always felt that some of the best movie one-liners have been uttered by fictional practitioners of Science (yes, with a capital S!). For a long time, my favorite was "Back off man, I'm a scientist!" by Peter Venkman (played by the inimitable Bill Murray), which has the extra advantage of being part of the fantastic movie that is Ghostbusters.
On my last plane ride, I sat through the very so-so "Land of the Lost," which features Will Ferrel as paleontologist Rick Marshall. The movie itself was pretty lame, but people sitting next to me were jarred awake when I burst out laughing when he screamed: "Science shows no mercy, and neither do I!". It's not quite on the level of the Venkman one-liner above, but I thought it came pretty close. Anyone have any other good ones that come to mind?