[kennu]

I also recommend Things, because it's an app that makes you feel good if you're into OS X and iOS style user interfaces. I bought it years ago, but truly started using it when they got the Things Cloud sync working.

So now I always keep it open on all my Macs (I switch between 3). It's always up-to-date, shows the number of tasks pending for today in the Dock icon, and it's comfortable to very quickly switch to the app, and create new tasks or mark old ones done. And when you're procrastinating, you can organize the tasks into projects and drag'n'drop them around, enter tags and descriptions, etc.

I think you can achieve the same with any todo list app or even text files, but Things makes it look and feel nice.

[pooriaazimi]

Have you tried OmniFocus? The Mac client is just fantastic (if you take the time to learn and customize it). And v2.0 (due in seversl months) is even better.

Of course, you have to learn GTD system to get the most out of OmniFocus. It's something that'll greatly improve your efficiency in the long run, so I think it's worth the time you invest.