Fearless

In my post about motivation (Money) - I forgot one basic motivation that some people use to drive their efforts: Fear. It could be a fear of failure, or a fear of losing their job, or a fear of embarrassment. But any sense of fear resulting in you putting in the maximum effort you can to accomplish a task to reduce the feeling feared outcome is a source of motivation.

I'm not sure how ethical (or even legal) it would be for a manager to prey on an employees fears to coax their best effort...but not all managers out there are paragons of ethics (thinking Tom Parkinson, former CEO of Hydro One)