Protestants used to joke about denominational differences. They don't anymore, maybe because most don't know what makes the denominations different from one another, and thus can't provide fodder for jokes. Catholics used to joke about religious orders. They don't anymore, maybe because there are so few members of them, or because they don't wear distinctive garb of the sorts that used to inspire jests.
Back when they did, a familiar joke had a Benedictine (O.S.B.) and a Dominican (O.P.) arguing about which was the best religious order. After having fought to a draw, the two decided to take it to the Lord in prayer. As their prayers rose in the chapel, a piece of paper floated down, bearing a message: "They are both good religious orders. (Signed) The Lord, S.J."