For early team members, I would always look for their strong belief in what we are building, because if the believe in it, they will be committed to our success more.
Afterwards, I would look for a combination of skills but the most important is responsibilty, being resourceful and ability to learn.
Excellent question to reflect on my value as a team player! I guess I'm an integrator who creates common values and a common goal. I love to unite people into a team with the help of corporate culture traditions.
The ability to do think ahead and not rely solely on what you tell them to do. When they see a problem in the business and solve it on their own for you, that is the best.