I have had good luck with a laser pointer before, but not on every fish. I had a green spotted puffer that I would "play" with by feeding him ghost shrimp, loads of fun watching it hunt those shrimp! It really seemed to be having a good time!
If you have pbass, get a string and tie a ball or glow stick on the end of it and spin it in circles in front of the tank. The pbass wil rush to the center of the tank and start gulping like crazy.