I did manage to complete the first coat of paint (Behr's "Corn Husk Green"), but another coat is still needed. D and I have been butting heads over painting the concrete floor, but I hope to prevail and paint it dark brown.
We opted against a real renovation (drywall, floors, insulation, heating,plumbing, windows, etc.) primarily because we don't want to do anything that can't be easily "undone" come winter, when we will need to store a snowblower in there.
Basement/concrete paint in Behr's Corn Husk Green
D installing rubber-backed 95%-recycled "garage carpet" from the Big Orange home improvement store. You can actually drive a car over it, so it'll be perfect for snowblower storage. It was our most expensive purchase at around $6 per 18" square.
We tried to keep the modular carpeting a bit away from the walls, just in case the "waterproof" paint isn't quite as resilient as we hope.