Robert Nisbet has been a seminal influence in my life and intellectual world-view since I've read his work. I can't say I've read all of them, but the most important or popular. I think libertarians should read him because I see his work as a great critique of the state from a traditional conservative's perspective, and some of his prescriptions vital to combating the state.
Mr. Brad Lowell Stone's bio I haven't yet read, but works I recommend are below.
The Quest for Community: A Study in the Ethics of Order & Freedom
Twilight of Authority
The Present Age: Progress and Anarchy in Modern America
Prejudices: A Philosophical Dictionary
A bonus is he has a great writing style.
malo periculosam libertatem quam quietum servitium
I am an aristocrat. I love liberty; I hate equality. - John Randolph of Roanoke