Given how much I do have, I'm likely to choose something from that. I have the Argonautica, all of Aeschylus, Sophocles and Euripides, all of Aristophanes (obviously, we're talking surviving works), the Enneads by Plotinus, some early Church Fathers (Basil, Clement, St. John Chrysostom), Ptolemy, Manetho (I like Egypt a lot), all of Plato, some assorted Aristotle, Thucydides, Herodotus, Plutarch, Procopius and, of course, Homer. It's a mix of Loeb Library and Oxford Classical Texts. The Herodotus is in two volumes of the OCT so that might be a good one to try. It's been a long time since I read anything and my main thing will be vocabulary (I might struggle to actively conjugate some obscure forms, like an aorist middle optative of a weird verb or something, but I still recognize forms when I see them).

I took a look at Lysistrata, actually, and it seemed pretty straightforward, except for some jargon, but since it was so obscene I think I'd like to learn the jargon anyway...

I still don't know which one I'll go for. I suspect I'll still opt for the Aristophanes, since it's shorter, but I might to Herodotus. Would you follow either of those?