I had a male Nandopsis haitiensus that would flip his tail and try to splash me every timeI got close to the tank, it was the fish with the most anthropamorphic personality I've kept. [/URL
Had a pair of niger triggers, they would spit water at me if they wanted my attention.
As far as most engaging? Probably a tie between oscars and bluegill, taught one of my bluegill to jump thru a hoop! And if he thought there might be food he'd beg by wagging his body so hard you'd think he would hurt himself, he also enjoyed petting
Schoolers are always cool to watch if you want fish that interact with each other. And there are many schoolers to choose from. I like watching my giant danios and rainbow fish. They are fast, spunky, and a bit aggressive at times.
My current favorites for interacting with me are my male gt, male flowerhorn, and gsp. All three are fun and engaging.