black pacu, i have had a single one die, and a pair, all were around 18". my red belly is doing great though 12-13" and i got it at 1". im picking up a 13" red tomorrow hoping it is only the blacks that i have problems with.
as for wishlist that i just cant keep YET. arapaima gigas, asain aro, channa.
edit. also cant keep a mystus wickii due to lack of a free empty tank.