Philosophy is essentially a fandom. If they're geeks they'll love the details and drama.
Philosophy does develop the mind but not in an interesting or useful way even from a philosophical point of view. Beyond Wittgenstein's take on philosophy as therapy is Zizek's (implicit) take on philosophy as entertainment.
Zizek is right.
So promote philosophy as fun rather than useful and geeky rather than literary and you won't go far wrong.
Personally I find Stoicism useful. And I suppose that other schools of thought (or subsets of other schools) could be useful, and/or I might even be "using" these without tracing these to a specific author.