Same with me - much of it IS obscurantist ill-written pretentious nonsense. But not the books I mentioned, though yes, or rather no: I do not think you are "mentally too retarded", but it simply is a LOT of text, including in the later volumes some maths and logic (that is clearly explained), and there are more interesting things to do in spring.
But it IS the sort of answer I would and think I should give to your question, and so I gave it. It's fit for healthy enthousiasts only, but it will answer a good part of your original question
An often downloaded short piece on my site in this connection:
Title: Why philosophy is important
The only writings that really stuck (besides Jung, of course, tho technically he's not a philosopher) was Nietzsche. I was especially fond of Thus Spoke Zarathustra. There are so many outrageously good quotes in that book. Some of the blatant egomania of it makes me laugh out loud! And then there are the powerful truths as well. My favorite, as an artist and a song writer is the one about writing with blood:
"Of all writings I love only that which is written with blood. Write with blood, and you will discover that blood is spirit."
And this one: "The experience of all deep wells is slow; they must wait long until they know what has fallen into their depths."
"Flee my friend, into your solitude, and to where the raw rough breeze blows! It s not your fate to be a fly-swat.
Thus spoke Zarathustra."
You're quite right he is a truly great writer. I reread "Also sprach Zarathustra" completely last autumn, for the first time in some 40 years and indeed it contains many great quotes and - more or less hidden - insights into the human-all-too-human (also a Nietzschean verbal coining).
I can't quote back at you on the moment because (i) I have it in German only and (ii) I can't find it on the moment (and just woke up, and first answered my Choir Mistresses word games and then you), but mind you that there are also at least two sections in it with the Blond Beastie prose Himmler loved, while admiring himself in the shine of his own boots. (I can tell you later if interested which ones.)
But Nietzsche is a truly great writer, and I like his "The gay science" (a bit of a misnomer in these po-mo PC times, for "Die froehliche Wissenschaft") best (and most of his criticisms of science make sense or are true).
O yes: I do not know how well he translates in English. Walter Kaufmann (originally German) wrote a book on him that is good, with his own translations, that are good - but even so, a lot (assonances, alliterations, rhythm, subtext) gets lost, even in a fine translation by a German native speaker who understands him well.
Finally, personally I don't like Jung at all, but I can see why artists would like him. And since you like Nietzsche, here is a HOT tip:
There are - I think, just woken up - 6 volumes of his in Everyman's Library. He is the Montaigne of England (better than Bacon, who showed his verbal stiltwalking abilities in his 'Essays' too much) and lived from 1778-1830.
Hazlitt is truly amazing, and the main reasons he is not better known than he is are that he was such a radical in many ways, and also was "The Prince of Polemicists" as - I think - A.C. Grayling's wrote.
There is just a little here of him on my site:
Title: Philosophy - Hazlitt-index
The best edition in one volume of his writings, with a good introduction is
"Hazlitt - Selected Essays"
Edited by Geoffry Keynes F.R.S.C.
London: Nonesuch Press
I'm afraid it is only available in good university-libraries and in antiquariats, but it is one of my favorite books (and Geoffry Keynes was the brother of John Maynard of that name, the economist and probabilist, while "F.R.S.C." means Geoffry was an eminent surgeon). The Nonesuch Press was Virginia Woolf's and others.
And now I proceed to wake up.