Well the obvious one is clowns of course.
-Check out court jester (aka rainford's) gobies. Omnivores but they will eat algae and also CYANO (this is not just an anecdote but documented)
-Pink streak or pygmy tanaka's wrasses. They won't get as big and mean as most other wrasses. The Pink streak is even too small to go after smaller shrimp like sexys if you have any.
-could also do a shrimp goby/pistol shrimp pair
-springer's damsel which is small and not aggressive like most damsels. Very active swimmer and a great blue color
-hawkfish (don't put them with any shrimp even cleaners)
-clown gobies (careful with these guys and SPS frags they like to nip which does not harm established colonies but can stress out smaller frags)
-radial filefish, especially if you have xenia (go captive bred for sure)
-captive bred mandarins
Consider inverts too. Smaller tanks are a good place for porcelain crabs, pom pom crabs, sexy shrimp, etc.
