Finally this summer, we unsealed three of the windows and put in screens, and today, for the first time, I actually propped them wide open, and discovered a marvelous cross-breeze that makes it far more pleasant down here. It's still only a semi-finished basement -- the ceiling is less than seven feet, so it'll never be legal living space.
But I'm very short, so the low ceilings don't bother me, and our workout space and craft space and tv-lounging / Wii game space are all down here, and I am here to say windows that actually open are a good thing.