I've used Taskwarrior (`task`) since last summer to manage my to-do list.
I'm a big fan of simple, console-based tools, so Taskwarrior was right up my alley. Best of all, since I have Taskwarrior on my Linode, I can SSH in to view, add or complete tasks from any computer or even my phone!
If you're looking to finally start doing your to-do list, Taskwarrior can be a great aid.