lots of cichlids develope nuchal humps. synspilum, most midas types (citrinellus, labiatus, zaliosus, amarillo, sp. chancho, xilaoensis, etc.), trimac (not much of one though), festae (again, not much of one), haitiensis, ramsdeni, most Herichthys (some larger than others--cyanoguttatus probably grows the largest of this group), most Cryptoheros (convict, sajica, spilurum etc. but some grow very small nuchal humps like honduran red points and nanoluteus), dovii, grammodes, some geophagus, peacock bass etc.
frontosa are incredibly beautiful and males can grow rather large humps. one thing about them though...it is possible to keep a single frontosa, but they'll do much better in a small colony of 6-8 with 2 males and 4-6 females. they can be kept individually but will thrive much better in colonies.
