I think it depends on your stories. I aim for the best story instead of the most fitting essay. Yes a school may love a leadership essay but if your material is weak for that you are better choosing one that you can hit a home run on.
My advice, brainstorm and idea for each. Spend a night or two thinking about which one you can develop the best and then use that. I am partial to teamwork, leadership is easily worked into the why mba, career goals, work experience essays. Teamwork seems to be one of the hot buzz words in b-schools (much like my least favorite: holistic)...so if you have a great teamwork story that can be a really good choice. That also allows you to talk about what you learned from it and what you will bring to the table at the school.
Then again its 11:30, I have been up since 5:30 and got no sleep last night so the above may sound like babble.