If you’re gonna do just one, I hear Anthem is the closest to being a decent novel. But I’ve only personally managed The Fountainhead (oh my god, don’t) and part of Atlas Shrugged (after the priming of Fountainhead, I could not get far), plus way too many of the essays and enough of her book on epistemology to know I didn’t need to keep reading (“ok so the fiction is terrible as literature and is entirely unconvincing, but maybe the non-fic is better?” I reasoned. Nah.)