I have to say Chocolate cichlid as well. My ex-roommate had a full grown one in a 75 gallon with a common pleco. That cichlid was the coolest looking, most mild and curious cichlid I've seen. Before I moved out I got rid of some of my fish and put a 3" clown loach and two 5" shubunkin goldfish in with the Chocolate cichlid and pleco. The chocolate cichlid could have cared less. I thought for sure he'd go at the small Clown loach, but they're all still in that same tank 2 years later.
Ya gotta get a Chocolate, you won't be disappointed.
Yeah, Chocolate.