While at ZURB, one of my favorite projects was Samsung Milk Music for web and TV.
A short (5-week) project, we were contracted to create an interactive prototype in HTML/CSS based on After Effects mockups provided by the client. I handled the JavaScript and collaborated with another designer, Jonathan Smiley, who created the CSS effects and developed the SVG masking technique for the slider bar.
The original requirement was that the code work in the latest version of Google Chrome and be suitable for handing off to a development team. After delivery, however, we recieved feedback from the client that they were considering using the JavaScript I had written (structured as a jQuery plugin) for the production version of the app (plus additional polyfills to support SVG masking in older browsers).