Philosophy:

Nichomachean Ethics | The Selfish Gene | Objectivism: The Philosophy of Ayn Rand | Dao de Jing

Everything I've read from Cicero has been good (only a handful of orations, I remember "On Friendship" particularly)

Language:

Nonviolent Communication (but don't get too formulaic in application) | Metaphors We Live By

Lighter reads (just random things I enjoyed recently): Medici Money | Reading the Forested Landscape | A Cow's Life: The surprising history of Cattle | Fat of the Land (Steffanson)

Anything on Mises.org for liberal politics, but especially Rothbard's "Anatomy of the State", Etienne de la Boetie's "Discourse of Voluntary Servitude", HSH Hans-Adam II's "The State in the Third Millenium" and HHH's "Democracy: The God that Failed"

Anything on Mises.org for economics, but especially Per Bylund's new "Primer" (at least at a more introductory level)