what is the most comprehensive History of Economic Thought book for an undergrad? Which Book or books would you recommend for an undergrad to learn about the history and evolution of economic thought and theory, and why? 
There Just so many of them out there and I just don't know which one will be best.
the one I was thinking of getting was Ekelund &amp; Hebert's A History of Economic Theory and Method but am not sure about it.
My suggestion is not necessarily the most comprehensive, but "The Worldly Philosophers" by Robert Heilbroner is very enjoyable.