Name one quality you think is essential in a team mate.

Alive - they are alive.

A big one for me is honoring your commitments!

results-driven

I think it's common goal, because people can't come together when they have different motives

Empathy. Empathy towards their clients / users. Empathy towards their colleagues. Empathy towards their employers too. Empathy for themselves.

Loyalty is important, especially in a founding team.

Nice

Passion for the project. Hands down.

Compassion - for both your teammates and yourself.

Reliability