For personal finance -- Dave Ramsey's Total Money Makeover is simple and effective. I haven't read Ramsey's EntreLeadership (a book on running a small business), but I will in the near future.
Henry Cloud's "Boundaries" is a solid personal relationship book -- on setting and maintaining effective boundaries in relationships.
For general personal growth and career -- "Seven Habits of Highly Effective People" (Steven Covey), "Integrity" (Henry Cloud), and "Quitter: Closing the gap between your dream job and your day job" (Jon Acuff). I've read parts of those, but not all of them. They're good, and recommended by several sources I trust.
Money: something by Motley Fool on investing.
One of the best books for advice in the work world that translates to life is "How to win friends and influence people" by Dale Carnegie. It is a great book that has advice that covers a multitude of things.
I'm not sure it qualifies as a must read (certainly not for "every man" as the OP asks), if it only does so for a specific religious group.
Here's a second endorsement for How to Win Friends and Influence People. Great for work and personal friendships.
Rich Dad Poor Dad by Robert Kiyosaki. He is kind of a 'get rich" guru and I find alot of his books are fluff that only benefit him, but this, his first book, has some good, common sense ideas about money that really changed my way of thinking and put me on the right track.
Albert Ellis and Robert Harper, "A New Guide to Rational Living"
Robert Persig, "Zen and the Art of Motorcycle Maintenance"
Some might think I am losing it, but Hitchikers Guide to the Galaxy.
Sometimes we just need to learn to realize the absurd in the every day and learn to do the absurd right back....or Don't Panic
I can recommend three books that I've read on one topic that has been of importance to me. I'm very introverted, which brings on a lot of stereotypes and misunderstandings by others, and has been a great source of shame in my teen and college years. If you're introverted, these books will help you to understand yourself and to identify the strengths that you naturally possess. If you're extraverted, these books will help you to understand the quiet ones in your life and recognize how much they have to offer when allowed to operate as they are. Both types will be challenged to stretch themselves.
The Introvert Advantage: How to Thrive in an Extrovert World by Marti Olsen Laney
Introverts in the Church: Finding Our Place in an Extroverted Culture by Adam S. McHugh
I'm currently reading The Power of Now by Eckhart Tolle which is a new agey, but interesting way of looking at the world.
For a more manly suggestion, I'd recommend the novel Love and Glory by Robert B. Parker which is not a self-help book but has a lot of great insight into how a man should live.
Also, Once an Eagle by Anton Myrer - required reading at West Point and another book that hides self-improvement in a great story.
I like 'The Way of the Superior Man' by David Deida. A little Woo-Wee but, all "self-help" books kind of do that.