I've taken a number of Halo character tests and for most of them came up with Master Chief. Here's a fusion of the Master Chief descriptions:

You are the Master Chief (Spartan-117). You are a take-charge, adaptable person. You are a leader. You are very brave – even when you are scared to do something to tough it out and do it anyway. You are loyal and dependable, and always get the job done. Your friends mean a lot to you, and they respect you. You do not glorify your violent actions, but merely do what has to be done. You do not hate the enemy; you kill because it is your duty. It is not your job to make things suffer, it is to win battles. When you speak, you speak in terse, softly-spoken, one-line dialogues and have a man-of-action demeanour. You have unseen reserves of humour and honour. You are enigmatic, coolheaded and all business.

I think that's an 80-90% accurate description of me.