Back then I loved UltraEdit. It was the fastest editor at the time and could open even the most humongous files.
Since then, I've used notepad2 for quick editing. And even for coding. Really loved notepad2. It could only edit one file at a time but that was part of its charm. I would have multiple notepad2 files open while coding.
Back in the DOS days I used Brief, Multi-Edit (syntax highlighting!!) and the Borland SideKick TSR notepad, remember that?
Nowadays on Linux, I code and write everything on Vim. Can't live without it. Cured my carpal tunnel too because I don't have to move my fingers to use the arrow keys or mouse.