When I first saw CoffeeScript I thought it was the best thing since sliced bread. I mean, it's beautiful to look at (and enjoyable to write). I was positive that it was going to replace JavaScript in my toolbox. Except, for whatever reason, it never did. It may just be because regular old JavaScript is already familiar, but whenever I needed to knock out any client-side code I'd have half the thing written in JS before I'd even think about CoffeeScript.

I guess at the end of the day syntax didn't end up being a killer feature that I needed. I still think CoffeeScript is awesome, but it doesn't solve problems that I can't already solve in JavaScript.