I can't put together anything near an inclusive list as I started reading more than one book a day when I was 10, then three a day by the time I was 13, and until the past few years I always had about five going on any given day. I would just stack 'em when I was a kid and teen, and work my way through the stack while eating Ritz crackers.
When I was through, at the end of a day and leaned over, the pressure behind my eyes was intense, kinda scary but it didn't stop me. I had something I wanted to know, and I couldn't put it into words. Besides, no one around me seemed to have this question so I kept it to myself, and looked for authors who shared it too.
What I was looking for, I can say now, is the difference between what we appear to be--to ourselves and others--and who we really are; what some call the difference between our personality and our Essence.
So, here, I'll stick with those who've had a strong influence on me in the last 10 years or so, except for an occasional book that pops in my mind and seems worth putting down:
1) Everything Paul Tillich wrote, starting with Protestant Era, then Shaking the Foundations, and on chronologically until he stopped writing--or I stopped finding, being able to afford his books even used.
He is considered by many to be one of the greater theologians--and philosophers--of the 20th century, and while many considered him a Christian, many more called him an atheist as he saw The Ground of Being as God--not some Big Guy in the Sky.
2) Erich Fromm beginning with Escape From Freedom, then Man Against Himself, The Sane Society (again, chronologically, whenever possible).
3) The Perennial Philosophy by Aldous Huxley is wonderful because, in large part, he introduces his readers to the best spiritual and wisdom writings and writers; after that, we can then get the works that call to us like Tao Te Ching, Tibetan Book of the Dead, and some writers such as William Law whom most have never heard of, let alone read (I was in that group until I read The Perennial Philosophy, because then I picked up William Law's, A Serious Call To a Devout and Holy Life). Aldous Huxley quotes a lot from the Buddha's sayings.
4) The Bhagavad Gita translated by Eaknath Easwaran
5) The Self as Agent by John MacMurray and all his other works, going chronologically as I like to watch the searching and finding unfold.
6) Charlotte Joko Beck's books, Nothing Special and Everyday Zen.
7) Ajahn Chah's books, especially Being Dharma: The Essence of the Buddha's Teachings, but most everything else he wrote, so second one would be Food for the Heart. I started with Everything Arises; Everything Falls Apart.
8) Mindfulness in Plain English by Bhante Gunaratana (no ritual, no nonsense).
9) Breath by Breath by Larry Rosenberg
10) Don Richard Riso and Russ Hudson's books on the Enneagram.
I started with Personality Types: Using the Enneagram for Self-Discovery. Now I am reading The Wisdom of the Enneagram, and Discovering Your Personality Type, which has a questionnaire and emphasis on how to avoid mistyping yourself. I'll finish up with Understanding the Enneagram.
I reread books of this kind--and many I can't jot down here. If a book isn't worth rereading and referencing, it's just entertainment, and I used to read a lot more of that; of fiction, when I was younger.
I think if I had to say what draws me now, aside from philosophy and psychology--a mix, and included in that, spirituality, but not the "salad bar" or watered down, glib kind... it would be writing that is offered for us to grow into our best selves.
So, whereas when I was younger I read a welter of writers--no outside guidance until college when I took an English class whose instructor used a thick, wonderfully diverse Norton Reader, I picked an area of interest then picking it nearly clean, e.g. all African American writers; all lesbians; all Indian poets and so on--all sorts of categories, I would move on to another area of interest, moving through the years.
Now, I am tightening the circle, and it does seem to take on the shape of a circle now as most of the writers I am reading at one time or another reference one another.
I wrote professionally for more than 30 years; I taught English literature; I was a literary critic (for a literary journal); I wrote using a variety of forms just as I read various forms from essays to poems to flash fiction, short stories, novels, et cetera.
I am reading in preparation for a particular work, and while I can't summarize it, I can say that any book that is not in some day redemptive, i.e. one that does not map out a life of confusion and chaos leading toward something more whole and integrated is not worth reading or writing.
So if I can't do that; if I don't have the focus or the physical health and vitality, I'll keep reading other Seekers, and be grateful I can still do that.
I have six book crates and three DIY shelves filled with books, and some overflow. I plan to weed through and let go of anything that will distract me from my searching, so I don't imagine I will have many books when I am through with that, much like it has been written that Pascal had three books with him when he died.
Although I do not know the names of the books he had with him, I understand why he had so few; and I consider him a good role model in this area, at my age.