Todo lists fail because they lack consequences. If you don't do something on your list it's no worries, still there the next day. And the next. And the next.

Calenders work because they have an implicit deadline. Todo lists should follow this same philosophy.

What I would like to see is a todo list where the list is empty at the beginning of each day. So you only can put things on your list that are achievable by the time you go to sleep. This means if you forget something it simply disappears. You have to put it on your list for the next day.