gm-mio
Graphicsmagick with an extra function for scale-cropping images:
var gm = require('gm-mio');
gm('/tmp/lol.png').scaleCrop(256, 128, 50); // scale to 256 * 128, slicing off the top 50 pixels
Useful for slicing images into pixelated banners. Extremely useful. Will change your life.