seaduck, look into the fairy wrasses or flasher wrasses. i recently found out about these guys and plan to get one or two for my new 65 gallon.
other nice fish are small clowns, royal grammas, and most damsels. (my royal gramma is constantly attacked by the blue damsel, damsel leaves the clownfish alone though.) firefish are good if you have a form of a lid.
clown gobys and neon gobys are neat. just make sure you dont have an overflow. i lost my neon goby to my overflow...
so many great fish. i had a mandarin in my 10 gallon but had to give him away to someone with a 180 gallon tank. but i can think of several fish that are much more colorful than mandarins and much easier to keep alive. (flasher wrasses being top of list)