NFOPad is a small, fast and flexible text editor and NFO viewer with numerous options.
It is a clone of Microsoft's Notepad but much more customizable and with lots of additional features yet maintaining the minimalistic look. NFOPad also supports NFO files with ASCII art. The file extension is used to determine whether to use an ANSI or ASCII font. NFOPad also fully supports Unicode.
While there are many NFO readers, don't be fooled by the name - this does have the advantage of being an excellent text editor should you need one with the occasional ability to read NFO files that many others lack. It's easy enough to use but has many features available when you want them including word wrap, alpha blending, font selection, search and replace, shell integration, printing, and more.