Interesting replies.
Personally, I use a Mac program called Coda by Panic. It's not exactly cheap, but you get a lifetime license with it. It has tons of pre-built features, as well as extensions that can extend on what it already does. I think I like the built-in server access (file, terminal, SQL, and source control) that doesn't require a separate extension/program to do.
However, if I'm editing a single file, I'll do like mentioned above and use Notepad++. It's quick and easy to make changes.