I came accross an asteroid that wasn't rotating and me being me decided to land on it. I took a bit of damage getting there but I think it was worth it for the picture.
People have been "landing" on very-slowly-rotating ring rocks since before Horizons came out and we couldn't "legally" land on anything except landing pads. Maia Posidana'a first travelogue thread has several examples from those early days; the link points to just one of them.