hi,
There are so many.....
Kiekergarrd....Descart...it depends I suppose..tis very exciting...From Arisotle to modern Philosophy and Social Science. An eclectic mix. The Waterstones section on philosophy is good as are necessary books for study at universities, past and present.

You should ask,
Why do you seek to study any thing at all?

If you answer, because "I am responsible for my own behavior."

Then you have some understanding.

Now very few philosophers made these connections:

1 The human mind is responsible for human behavior.
2 The mind is wholly linguistic by function.
3 There are two, and only two primitive branches of language, logic, such as common grammars, and analogic, such as human behavior, crafts, geometry, etc.
4 Both branches are derived from the definition of a thing, and therefore must say the same things.

5 The only power a mind has is language, therefore the principles of language by which we do our own work is "God."

This stance one will find in Confucius, Plato, the Judeo-Christian Scripture, etc. One must learn that we learn by example. One has to learn to read and understand metaphor.

Great philosophers also learn via Lucid Dreaming. Lucid Dreaming is an Analogic, which most people cannot comprehend as a language.

However, what you think they are saying is probably not your first, second or even third impression. The human mind takes a long time to mature and will more often than not be wrong.

Search the Internet Archive for free books. You can find original books in digital format, audio-books, video-books all for free.

The more you understand, the more you will comprehend what at first you did not suspect-the human race is very, very, young.

the philosopher that will most benefit the self, is within but one self...

if one draw within it self, to connect to the plume of all knowing, within it self and each...

then beware, for from within come grand deceptions to falsely bedazzle with only but what one self wishes to hear, believed only by that which seeks wisdom for it's own minds picture of a happy life for it self, and that which seeks knowing to secure the notion of self as wise for vanity...

if one hears these things from the plume, the fountain and deliverer of of all knowing, and likes and revels in knowing them, it shall come to be some and even long time before uninterrupted self happy can or shall occur...

then beware, for from within come mighty grand lovings to teach one self how to think and do differently than it did unto all others.

if one hear these things from the plume, the fountain and deliverer of all knowing, than take joy in being no longer able to be deceived by only wishing to hear what one wanted to hear, and happy for this one shall be uninterrupted and never cease.

for the thoughts one wish to hear decide all that occur as reality.

My favorites so far from which I have personally drawn:

Being and Time by Martin Heidegger
Nicomachean Ethics by Aristotle
Republic by Plato
Symposium by Plato
Summa Theologica by Thomas Aquinas
Principles of Philosophy by Rene Descartes
Metaphysics of Morals by Immanuel Kant