RightNote 50% off - US $15 and US $30 (Standard and Pro, Resp) @ Bauerapps

RightNote is hierarchical note-taking software, ala. free KeyNote. I use it both, hence, can recommend.

If you value data and can store yours hierarchically then this software's for you, regardless of price. I have KeyNote files spanning almost a decade - I never discard learnt information and there's never a workday when I don't add or refer to my RightNote and Keynote files.

Compared to KeyNote, RightNote handles tables properly (and is able to store compressed images), however, it doesn't seem to toggle word-wrapping.

Microsoft OneNote isn't a hierarchical note-taking software, but it's main advantage is that it has an iFilter hence can be searched using Windows Search.