When I worked in the bagroom at Westwood CC outside of Cleveland, we played a lot of one club golf in the late evenings. It was never anything too serious, just for a couple bucks with the assistant pros, but it was close to the most fun I've ever had on a course. All scoring expectations are gone and creativity is paramount.
We usually hit it around with a five iron because that gave us options more options than a hybrid on shorter par 3s. There were really only two holes where losing a ball was a possibility, 4 and 17. A long iron worked everywhere else.