Notepad++

PSPad

There are many, many so-called "notepad replacements", and surprisingly, most of them are pretty good. I like Notepad++ for a few reasons. It's Open Source. It does everything I could want it to do. It's fast. It's been around for years. Here's some of the features:

Syntax Highlighting and Syntax Folding
Auto-completion
You can edit several documents at the same time.
You have two views at same time.
Regular Expression Search/Replace supported
Drag 'N' Drop
File Status Auto-detection
Zoom in and zoom out
Bookmark
Brace and Indent guideline Highlighting
Macro recording and playback

PSPad is an excellent text editor as well. It's more of a programmer's tool than Notepad++ and includes features only a programmer or web developer would ever need such as links to a compiler, a hex editor, and a built-in webserver. Unless you're a developer, stick with Notepad++. If you are a developer, you probably have already tried PSPad.

http://notepad-plus-plus.org/
http://pspad.com/