Most are made up and silly.
The only one I've liked was in college I did a "communication style" one. Where it showed a bunch of different like emails, posts, and conversations and asked which you preferred to receive and which you were likely to write.
10 years later I still think about it, cause the goal of the work was to talk about how if you're a certain communication style what to keep in mind with communicating with others. Like tips to not get frustrated with yellows who don't care about facts when sending emails and how to write emails that don't bore and frustrate people if you're blue. (I'm blue green. I can sometimes write long emails)
I thought about it the other day cause a guy was complaining about all these emails that didn't seem to say anything, they were just about feeling good, and he just wanted them to spit it out. Which corresponded to firey red getting mad at green.
So with that context, do you have any that actually had an impact on you?
When these 2 books are combined, they can be profoundly helpful:
https://www.amazon.com/Modern-Enneagram-Discover-Who-You/dp/1939754070/
https://www.amazon.com/Take-Care-Your-Type-Enneagram-ebook/dp/B084VVB64H/
It's the 2nd book which is the most-convincing ( because the improbable-recommendations it makes are sooo damn right, based on my last half-century of experience ),
but without the 1st book, the 2nd book has much less traction in one's understanding.
2 books on one's life-process-lopsidedness which can be equally-profound, are
https://www.amazon.com/Ayurvedic-Healing-Comprehensive-David-Frawley-ebook/dp/B003TO5EF0/
( do the ingredients-list experiment:
find your metabolism/"dosha", & identify which set of ingredients would be most-harmful for you vs which would be most-pacifying for your health, & make a meal where each course is a pair of dishes, 1 maximally-aggravating, the other maximally-pacifying, & see which your own body prefers..
Mindblowingly eye-opening, that.
All the meals I'd eaten, before, had been a mixture of harming-my-health AND healing-me foods, an insane "strategy" that hadn't been working!
Now, however, for all the years since I did the experiment, my health has been subtler & better a harmony.
Let the experiment-evidence decide for you, if your metabolism is one of the fundamental-metabolisms: then it should be clear-as-day. )
and
https://www.amazon.com/gp/aw/d/B0028UBEVO/
Again, both books are required for proper understanding.
The Yoga book shows you the kind of way you work-with your metabolism/"dosha".
The ingredients-list in the "Ayurvedic Healing" book is sooo fundamental to my health that I simply don't go grocery shopping without it, anymore.
This book is on the life-STAGE archetypes, like shattered-by-trauma
( the pair of "cards" "The Lightning Struck Tower" and whatever the crab-sifting-memories-in-the-lake-of-memories while the "wolf" and the "dog" try to get one off one's true-path through aversions or desires )
or having to disconnect from the outer world, in order to go deep within oneself to decide something important, re one's lifepath ( the choice/love card, card-6, iirc )
https://www.amazon.com/Wisdom-Tarot-Elisabeth-Haich-ebook/dp/B0716CHXJQ/
That one book I'd recommend getting the physical book, however: the archetype-stage illustrations are not included in the ebook.
The difference between it and ALL the other "tarot" books I've ever encountered, are..
I'm not saying to just become a believer in its symbolisms, but I definitely am saying that if you ever want to understand someone's sentience-stage, their life-state, you need to understand the stuff in that little profound book, and if any sudden change happens to someone, then that little book can help them know what they're needing to focus on, to continue living unbroken, un derailed.
It's an important psychology grounding.
Kegan & Lahey's "Immunity to Change" is on the 3 unconscious-mind development stages of adult human life, and how our unconscious-mind "fights off" growing-up/adapting, to protect dysfunction/inertia.
It's also important-as-hell for our lives.
Especially nowadays.
Daniel Kahneman's "Thinking Fast & Slow" is on the imprint-reaction mind, which I call Kahneman1, & the considered-reasoning mind, Kahneman2, and how Kahneman1 mind fights to prevent the considered-reasoning mind from having any say in anything it feels it "owns".
All ideology/prejudice imprint-reaction, left, right, religious, political, ALL of it, takes advantage of Kahneman1 mind, to try to own populations, & through them, countries/worlds.
It is the single most-important psychology book in our whole world, right now.
Communist "proletariat dictatorship" & right-wing "populist dictatorship" are both the same thing, fundamentally:
highjacking of the world for factional-supremacism, through Kahneman1 mind's mechanisms.
I stop here, as of the thousands of books I've dug into, those are the most important ones for profound understanding.