Mackay is good.
Joe Girard (sp?) is good, too. His thing is he was a great car salesman. The books of his might seem a bit out of date with certain things (he mentions in one that he always kept cigs and a bottle of whiskey in his desk for a "toast" after he closed a prospect, which helped overcome buyer's remorse), but for every one of those, he offers ten pieces of good sales advice that don't go out of style, which every entrepreneur needs.
Tony Robbins is good in that "do the things you know you need to do" way.
Funny, a but a good book for entrepreneurs is by Derek Jeter of the Yankees. Called something like "the life you imagine", it's good stuff in regards to envisioning something and achieving it.