Please do not post time-wasting comments like this. I asked a serious question and I would appreciate a thoughtful and useful answer.

My answer was serious. I've tried computer "to do lists" many times. None are as fast, convenient, accessible, or inexpensive as a simple notebook and a pen. Sometimes the best solution does not involve a computer.

I rewrite my tasks each day. This tends to have the side effect of making me complete those nagging little ones that sometimes seem stay forever.

To prioritize, I just put a little star next to the important tasks. I tried using different color inks and annotating with categories in the past but found this to be a waste of time.

It is a permanent record that I don't have to worry about backing up. I've got notebooks going back over 20 years now.

I guess one down side is that one cannot data mine it, I question the actual usefulness of such an activity.

I've tried pen and paper and it doesn't work well for me.

I have no time or desire to rewrite my tasks every day. There are literally hundreds of them, each with tens or hundreds of sub-tasks needing to be finished before the main task is considered complete.

Basically I want to use a computerized system because I believe that it will be far faster, easier and more flexible for me.

No where did you say the tool had to be online. I find paper and pen the best option as well.

it doesn't have to be online, but it must run on a computer. There, I hope this makes it clear that pen (or pencil) and paper is not an option ... :)