So far I have been using TextMate in an attempt to make my life easier and more efficient on the Mac.
It is overwhelming at first an not everything is where you think it is, for example, the preferences appear slim, but there is a lot to customize if you want to. I really enjoy the themes and the downloadable themes make colorizing the windows easy. There are many plugins and you need to get familiar with Subversion to install the plugins (called Bundles). It is one of those “wares” that need time to work on you, time to get settled into your routine and then it will be indispensable, I’m sure of that.
Line numbering (a necessity) is in the gutter area and not in the actual text file as some editors do, color coding via themes (mentioned above) is fabulous and VERY customizable.
TextMate can be setup to work with your blog to post and edit entries within TextMate. It costs about $50 US and will most likely end up in my “Mac toolbox”.