Oscars are obvious, that is why they are such big sellers. Mine certainly has personality, but so does the Jack Dempsey he lives with.
I like Gouramis, when I had them, they would come right up to me and nibble at my fingers as I did water changes or adjusted things in the tank. Angels are very personable as well, piggy, but personable. When I walk through our fish room, all the angels come right up to see me, hoping for food.
But my favorite are my sailfin plecos. I have one in each tank, and they both have completely different personalities. I think I enjoy watching them more than any of my other fish.