Preview HTML:
I use a very simple WYSIWYG editor (BlockNote) to create web page templates then it's Notepad++, XYPlorer, FastStone
Image Viewer, ColorMania, image editors, and see the effects of html editing quickly and easily.
TextFX:
It's just a general text tool - convert ROT13 back and forth, text to hex-16/32/64/128, Decimal to binary/octal/hex,
convert to upper/lower/proper/sentence case, and so on. if you have something like a list of names or want to see if a
pair of dice are not biased, you can sort the list numerically/alphabetically and quickly see if the deviations are
within the accepted (for randomness) square-root of the number of throws. I just find it a very useful plug-in.
DSpellCheck:
I already have 'ASpell' installed here, but when on the road with my sticks, I can switch to 'Hunspell'.
NppFTP:
I have local Intranet FTP servers that I can log into, editing and transferring files to and fro, and even log into this
machines own FTP server for easy access within the Notepad++ environment.
I tend to install everything I might need and leave it to usage over time to determine what I actually need.
Zak Hipp