For some time at work, I used Ultraedit as text editor, but without a private license, I used a lot of alternatives from Emacs to a combination of Notepad and the VisualStudio editor for private work. But I just came across notepad++
(Warning, ugly website), and wow, I'm impressed, that's a nice editor.
It features a built-in hex editor, undo/redo, tabbed documents, dockable windows, UTF support, word wrapping, wrap/CR-LF view, formatters for dozens of languages, XML pretty printing, macros, run-shortcuts, plugins, and works nice with huge files. Everything wrapped in a very nice simple user interface. And it's not only free, but open source. Very cool.