The amazing thing about CoffeeScript is that most of what it does is tiny little changes that shouldn't matter that much, yet the overall effect is huge. For example, string interpolation involves one fewer character than concatenation, yet the effect on readability would be hard to overstate.
A similar feature in another language is PHP's ability to mix in with HTML. It would be utterly trivial to convert the HTML sections of a PHP file to echo statements. Yet this tiny bit of sugar goes a huge distance toward making up for the language's short comings (also known as "almost everything else about PHP").