Here is what I would recommend to you honestly,a Oscar,Jaguar,Texas,Jack Dempsey,Green Terror,Severum,and even a Midas if you like,majority of those fishes are very active,but when a Oscar reaches about 9+ inches,they attend to slack a bit and stay in their comfort zone.Oscars either way will come up to the glass,when you are by it,even if they do become a bit lazy.