Is there any philosophy worth reading?

As far as I can tell, a great deal of "philosophy" (basically the intellectuals' wastebasket taxon) consists of wordplay, apologetics, or outright nonsense. Consequently, for any given philosophical work, my prior strongly favors not reading it because the expected benefit won't outweigh the cost. It takes a great deal of evidence to tip the balance.

For example: I've heard vague rumors that GWF Hegel concludes that the Prussian State (under which, coincidentally, he lived) was the best form of human existence. I've also heard that Descartes "proves" that God exists. Now, whether or not Hegel or Descartes may have had any valid insights, this is enough to tell me that it's not worth my time to go looking for them.

However, at the same time I'm concerned that this leads me to read things that only reinforce the beliefs I already have. And there's little point in seeking information if it doesn't change your beliefs.

It's a complicated question what purpose philosophy serves, but I wouldn't be posting here if I thought it served none. So my question is: What philosophical works and authors have you found especially valuable, for whatever reason? Perhaps the recommendations of such esteemed individuals as yourselves will carry enough evidentiary weight that I'll actually read the darned things.