Fortune has a good feature-slideshow on its website. It features captains of industries, astronauts and other successful people. These icons share the best advice they ever got. Watch the slideshow here.
The one which immediately resonates with me is the one given to Sam Palmisano, CEO, IBM. He talks mostly of 2 things - 1. Leaders don't make themselves centre of attention; they listen. 2. Career is not a linear progression, rather, it ought to be a little unstructured and horizontal.