Ask HN: Your favorite to-do list or task manager?

I have one large (and several small) personal projects to accomplish during the next year or two of my life (including building a new house) and one professional programming project to start planning. I think an online to-do list or task manager would be a help in terms of planning, scheduling and reminding me. I do not need a mobile app, instead I'm interested in a solution with great desktop interface. What do you use? Do you recommend it? If so, why?