Whilst I wouldn't go as far as Socrates in saying that 'the unexamined life is not worth living', I'm a real advocate of increasing self-awareness so that I can manage me, and lead others better.
As a result I'm trained to use a number of psychometric tests and, for myself, I'm always most interested in the ones that give me insights into how I might 'overplay' my strengths so they become weaknesses.
The Hogan Development Survey is a really good way to get insights on the darker side of personality and how you might get de-railed when under pressure. There's a great book that's been written that takes the Hogan Development Survey criteria and discusses them in terms of why CEO's fail, the behaviours that hinder progress, and how to manage them. Click on the link below to buy the book from Amazon - I'd really recommend it. And if you want to find out more about where you might be hindering your progress to being a great leader, take the Hogan Development Survey - I can help you do that if you get in touch.
Why CEO's Fail