I still get a little thrill when I open 'A Room of One's Own' and run into lines that feel built for essays. My top picks that I’ve actually quoted in papers and talks are "A woman must have money and a room of her own if she is to write fiction," which is perfect for arguments about material conditions and creativity; "Lock up your libraries if you like; but there is no gate, no lock, no bolt that you can set upon the freedom of my mind," great for pieces on censorship or intellectual freedom; and the compact zinger, "For most of history, Anonymous was a woman," which lands so hard in gender-history intros.
I also love the sharper, provocative opening from 'Mr. Bennett and Mrs. Brown'—"On or about December 1910 human character changed"—because it makes a bold chronological claim you can riff on in a thesis. When I teach citation habits to friends, I tell them to pair each of these lines with a sentence explaining context: where Woolf is arguing from, and how that maps onto your claim. Those lines are quotable but they sing best when you let them anchor a paragraph rather than let them stand alone as ornamentation, and slipping in the source—'A Room of One's Own' or 'Mr. Bennett and Mrs. Brown'—keeps you honest and persuasive