second the red devil...I am not a big fan of cichlids but my brother has one and they have great personalities and they are really aggressive...beautiful fish
Istlanum is my first choice. Trimac or midas is my next. A red tiger would be good but not as outgoing. Most male grammodes will hide all the time and they grow so damn slow it's almost as if they are shrinking. How about an H. carpintis 'Escondido' as they are great looking fish!