All portable, listed in no particular order:
- LibreOffice - I mostly use the Writer component as a much better and more reliable replacement for Microsoft Word, but more and more tools are seeing use as time goes on
- PDF XChange - excellent tabbed PDF viewer with basic editor components and a great OCR addition
- ShareX - screenshot program that allows for a remarkable amount of easy, intelligent automation
- Notepad++ - my text editor of choice for 6+ years now.
- Ditto - a bit strange to learn and use but super reliable, actively developed, and very customizable