Cool! From what I've read, the Congo gets the biggest, at around 39". I like the lower jaw species, like the endlicheri, but upper jaws are cool as well. Popular 20+ inch species kept include senegals and ornates-all of which are cool fish.I'm really blown away by all the cool poly pics. I've determined there isn't a poly out there that I don't like! Being true to my preference of bigger is better, I'll be concentrating on the largest species. Id like a tank full of 20+ inch beasts! First thing I'll do is start planning my build. Probably go plywood for polys. Been toying with the idea of doing a 10 foot bay style with three large viewing panels. Probably 6 sided. Something outrageous for sure!