Also try SciTE (http://www.scintilla.org/SciTE.html).
I discovered it a few months ago, and have been very pleased. It lacks a few nicities (config is pretty much all via config file(s)). It is fast, which is a real plus for me as I have a bad habit of closing a text editor only to discover that I need to edit "one more thing".
I would also recommend jEdit (www.jedit.org). It has many more options (via plugins) than SciTE; and a nice Windows right-click menu extension; but is kind of slow to startup (being Java), but pretty snappy once it is loaded.
Both projects are open source, and appear to be under fairly active development.