+1My first thought was Jack Dempsey but after thinking on it it would have to be an Oscar. In my more than fifty years of keeping fish I have had just about everything at one time or another. Oscars were one of the first fish I ever kept and because of that experience I gained a love for keeping aquariums that has stayed with me my entire life. Adults can be a little demanding due to the amount of waste they create but they are worth the effort.