A Convict cichlid. Quite personable, and stay around 6-7" max.
My aunt's boyfriend used to have one named "elmo" (lol). It had such a personality... I always thought it was thinking "I'm good, and your good. Just DON'T come near me." It would 'defend' itself against the mighty monster that was his hand.
-- It was in a 75g tank with 4 other medium sized SA/CA.