The best replacement for onenote is evernote.

The best alternatives to onenote are rated as following:
★★★★★  evernote
★★★  word
★★  sharepoint
★★  wiki
★★  endnote
★  outlook
★  evernote ipad
★  google keep
★  google docs
★  gobinder
★  journal
★  outline
★  scrivener
★  springpad
★  evernote which is better
  circus ponies
  notebook
  omnifocus
  simplenote
  treepad
  evernote iphone
  circus ponies notebook
  windows journal
  s note
  confluence
  curio

Your alternative for onenote is not listed? Suggest!
Speaking about onenote, one probably shouldn't forget about sharepoint.

Other search terms related to onenote and their ratings are:
★★★★★ sharepoint
★★ spen
★ office 2007
onenote
You have in mind a companion for onenote and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of onenote in all years. Click on graph for more.
onenote
evernote
word