PHP, and either a suitable framework (Smarty's OK for templating, but damn slow and bloated for specific needs), or my own little hack.
My reasonings are simple: PHP is easy to deploy virtually anywhere, RoR is still an infant, and requires proxying through Apache (lighttpd or otherwise), and although robust, just doesn't have the featureset that I generally want, or use.
RoR is prettier, but sometimes it's better to spend less time on making it beautiful, and make it WORK so you can make money, instead.
