ToDo List tools

How do you manage your ToDo list ?
I've tried different solutions but I didn't find the perfect tool yet.

First I tried to use my emails to manage my tasks. By sending emails to yourself and using some emails client features like flags, Gmail labels, or Mail.app smart folders, you can build something like a tasks list.
But a lot of features are missing: tasks hierarchy, percentage completed, deadlines, ...

Then I tried to manage my tasks on a wiki. It's fun to play with the wiki features, but after some days you realize that it takes a lot more time to edit a wiki page than a plain text file.

So, I went back to my old plain text file, and always kept a "vi ToDo.txt" running somewhere in a Terminal. Simple, but powerful, think about all the unix commands that you can use inside vi, like 'sort' to sort your tasks by priority for example.

This week I give a try to MyMind. Here are some screenshots.
Some good points: easy to use, almost as fast as a text file by using the key binding and an interesting feature, the map. This map allows you to make links across items, in addition to the items hierarchy.
But clearly, this application isn't designed to be a ToDo list manager, the notion of date is missing.

So to sum up, here are my needs:

tasks hierarchy

metadata: date, priority, deadline, % completed, (tags ?)

easy/fast to open and edit

multiple views by metadata

orthogonal links between tasks across the hierarchy

usable with OSX

Do you know the good solution for me ? stop managing my tasks ? :-)