chromis are great. Started my tank like that and still have a small school of them circling my coral with my other fish. Another good starter fish that are a bit more colorful and flashy are certain dartfish like the zebra barred dartfish. They swim in th open almost all the time, colorful, iridescent, and love to be in pairs or small groups. My pair are always together and seem inseperable. However, not all dartfish will tolerate each other. Clownfish are good if your tank is big enough (like 50 gal for a couple). I got rid of my pair because they harrassed my other fish just like damsels do and I had one yellow jawfish go on hunger strike by hiding in his hole until he starved to death.