I'm a new fan of crinoids (feather stars). I used to think they were sort of gross, even though I always have liked the patterns their arms can make. I love that they come in all sort of colors, and host so many interesting commensal critters in their feathery arms. By the end of the trip, I was checking out most of the crinoids I saw for clingfishes, shrimps, and squat lobsters. They are also great for curbing reef-destroyers (those divers who have problems with bouyancy or perception). If you touch one, they stick to you; on one dive I saw one of the guests coming up with two crinoids stuck to him. It was very sad, as they are quite fragile and may rip apart as you try to brush them off.