Regal / Pacific Blue Tang

Snapshot: Commonly known as the Blue Tang, it dazzles with an electric blue body and a yellow tail. Its striking dark lines start from their eyes, trace down their dorsal line, and loop above their pectoral fin.
 
Other tidbits: Can grow up to 25cm or so. Range extends widely from East Africa through the Indian Ocean and across much of the Pacific. Famously portrayed in 'Finding Nemo', this fish is a moviestar!
 
Bare bones must know: Live-rock fish-only system, or reef aquarium with plenty of swimming space. Mature and well-established aquariums. Well-lit aquarium.