The author has extensively explored various note-taking applications, including Google Keep, OneNote, and SimpleNote, ultimately transitioning to Outline, an open-source application that combines note-taking with personal knowledge management. Google Keep is appreciated for its simplicity but lacks depth, while OneNote's interface is seen as cluttered. Outline offers a clean, intuitive interface, supports markdown for rich formatting, and allows for interconnected note systems similar to a wiki. It integrates well with external tools and provides self-hosting options for data ownership. The author now uses Outline primarily for research, long-form writing, and journaling, finding it superior for serious note-taking compared to Google Keep and OneNote.