As far as to-do lists go, Do It (Tomorrow) is one of the simplest and effectivest (just made up that word). And the interface is eye candy. You can add to-dos for today and if you don’t feel like or it’s not possible to do them today, you just put it off for tomorrow. In fact, one of the main concepts about the app is putting stuff off for tomorrow. Procrastinators’ heaven.
How this works is that once you get tired of putting it off you eventually get it done. I’m currently using the web app and the android app. There are iPhone and iPad versions available as well.