The title of this post may seem oxymoronic, but there are cichlid species that don't have a "seek and destroy" mentality, especially if a single is kept. If you're looking for such a fish, you might consider Callochromis macrops, at least a female.
Most descriptions of this small cichlid suggest it is mildly aggressive, even to other species. Proving that cichlids can be highly individualistic, I have had a single female (see photo above) for well over a year and she's the most docile cichlid I have. She resides in my 75g Tanganyikan community tank with a variety of other dwarf Tangs and she is NEVER the aggressor. I even have some mild tempered cichlid tank mates that are not very tolerant of her. She doesn't get bullied but she does get chased off frequently.
Possessing enormous eyes, which is why their common name usually consists of the term "Big-eyed" or "Large-eyed," their bodies are shaped quite differently than most of your everyday variety of cichlids. Their feeding behavior also resembles that of the Geophagus genera - sand sifting, which is interesting to observe if you've never seen it.
To find more profile detail about C. macrops, a Google search will return plenty. If you're looking for something different in your tank that is active and curious, consider this nifty little cichlid.
The Cichlid Room Companion
Tropical Fish Hobbyist
American Cichlid Assoc.
African Cichlid Hub