Having been on both platforms (windows and *nix) I used a bunch of editors over the last 4 yrs. Here's thoughts and opinions on both

• Windows
  • Programmer File Editor
    Not much current development. I started out with this program before moving on to editors with more features.
  • Archnophilia
    Good program, fallen a bit behind on features compared to more current editors. Good for HTML editing
  • UltraEdit
    Used to use it. I have since converted to NotePad+ and gvim. Syntax Highlighting and ability to add commands to the menu bar make it useful for development.
  • Notepad+
    My standard replacement for notepad. All the features of regular notepad, with no file size limits and someother nicities. I like it because I can install it and even Microsoft apps will use it.
  • GVim
    Graphical Vim - What more can you say :-)
• *nix
  • GVim
    And I can use the same program on both OS'es :-)
  • NEdit (Nirvana Editor)
    Nice windows-style gui. Very comfortable for converts from windows or individuals who regularly work in both OS'es. Has syntax highlighting, macro programming, and other nice features for use as a programmer's editor.