In my time leading a guild I've wondered, what makes a good raid leader? I was never comfortable with the job and did poorly with it. Fortunately for my guild, there was someone who rose up to the challenge and I think perhaps he is someone I would idolize as a good raid leader.
First and perhaps one of the most important qualities of a good raid leader is self confidence. The ability to make and commit to decisions for the raid is important. And not only is it important to the raid lead, it is important to the raid team who will generally look towards the raid leader for assurance that what they are doing is the best and most effective. A raid leader who is strong in self confidence will inspire those who follow and bring the respect of those under his or her authority.
Second is self mastery and is just as important as the first. For if you cannot be your own master, how can you be the master of others? In raiding you must know your class well and be able to do the very things you ask of those around you. You must be able to think for yourself and act on your convictions and plans. And you must be able to control yourself in the face of adversity. If you can do this, you will be able to be assertive - rather than spontaneous and aggressive in your responses. And while sometimes the aggressive leader can get the attention of the team quickly, it is usually the calm one that will keep their respect and ultimately get the better performance in the end.
Thirdly, another important aspect of a good raid leader is their optimism. A leader filled with optimism will be able to convince others they have the ability to achieve levels of performance beyond what they think they can. The optimistic raid leader won't simply give up on something, they'll work around a problem till they find the solution and succeed. They will be willing to take risks and encourage the team to follow with them until a solution to the fight is found and overcome. They will not be afraid of failing a few times because they know in the end they will win out. And it is that positive attitude that will lead to victories for the raid team.
A final thought on what makes a good raid leader is their humility. The understanding that while you are great, you could not get to where you are without the people behind you. A leader who takes all the credit for the team's success causes resentment from the team. No one wishes to play with someone who thinks they are better than themselves. However, the raid leader who shares credit with the team will find the team's confidence higher and their desire to grow stronger as they achieve more.
My friend has been raid leading for my guild for a year now and has displayed these qualities and more. He has the respect of the raid team and his leadership has made it possible for our guild to have gotten as far as it has. Self-confident, a master of himself, optimistic and humble - he is an example of an excellent raid leader.