I usually just use Notepad, it's quick and easy to start up and use, sometimes I have to use Wordpad, I forget why, maybe for RichText, or because it handles files with only LF's and no CR's better than Notepad (unless Notepad has change since then), but I haven't really used Wordpad in years. For more involved stuff, like writing my book of essays, I use Word.

On Linux I use gedit, which is basically a small Notepad clone. I really don't like the way nano, vim, etc. work, it's not intuitive, everything takes thought and effort, and also experimentation since I cba to read the manual.