Surely one of the most unimpressive, boring people in technology. Her distinction: she was in the right place at the right time.
Marissa is very, very sharp. She can rub many people the wrong way (including myself) because she's almost always completely certain that she's right. However, she is right a good portion of that time, certainly more than most people I've met. And when she's wrong, she'll always listen to data that proves her wrong, and the issue gets dropped. I can respect that.