I liked Bossidy's "Execution" and "Facing Reality", like all such books they wander a bit but they have some good insights. "Managing Humans" was okay but I guess I may have come to it a bit later in my managing experience so it seemed pretty obvious. "The 5 dysfunctions of the team" is useful for understanding how to look at root causes of teams that become dysfunctional, can be depressing when you recognize your own team in its pages :-). And not a management book per se but "The Sociopath Next Door" was a useful read because it better helped me understand and identify people who were very different than I am in terms of their emotional investment in things.