• Justice -- fairness, a matter of rewards and punishment
• Judgement, which develops over time
• Initiative -- taking action in the absence of orders
• Decisiveness -- and be clear and forceful about it!
• Tact
• Integrity, because trust is essential
• Enthusiasm -- again, not false enthusiasm! Sometimes you'll disagree with the boss, but don't do it in front of subordinates. You should be able to overcome a single disagreement with the boss because you are so enthusiastic about your organization. If you disagree all the time, then leave!
• Bearing
• Unselfishness
• Courage -- which is not the lack of fear, but the ability to deal with fear
• Knowledge
• Loyalty, especially to the organization
• Endurance, both mental and physical

But remember, everybody has their own leadership style. Do what works for you, in the environment in which you find yourself. Not everybody is a Marine, or in the Marines!