I've tried a few syntax plugins and recently revisited some of them again. I came back to this one for it's simplicity. Plus, I love the fact that the look is so clean.
Also, and this isn't in the feature list...you can easily add this syntax highlighting to comments by simply wrapping code in
<pre class="brush:php"></pre>, where "brush" is the syntax you want to use. AWESOME!
Crayon Syntax highlighter has the option for use in comments, but it's messy and big overkill.
Hopefully someone gets back to updating this plugin, I'd hate to see it fade out with lack of updates.