Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Turtl - The secure, collaborative notebook
OneNote - Get the OneNote app for free on your tablet, phone, and computer, so you can capture your ideas and to-do lists in one place wherever you are. Or try OneNote with Office for free.
Tomboy - Apps/Tomboy - GNOME Wiki!
CherryTree - A hierarchical note taking application, featuring rich text and syntax highlighting, storing data in a single xml or sqlite file.
Omni Notes - Note taking open-source application aimed to have both a simple interface but keeping smart behavior