When I had oscars they would eat out of my hand and let me pet them or lift them out of the water for inspection.
There aren't many species you can say that about. Now, do keep in mind they get LARGE, if you're contemplating a new companion.
Mine "bites" me, goes out of the water about 5" inches to get at my hands so I don't "pet" him. But I do throw food and giggle alot.