Well, there are a lot of choices
Clowns, cardinals, gobies, some wrasses and many other fish are reef safe. Tangs are very popular, and reef safe, although a little more aggressive. A lot of people like anthias, although they're not such a good choice for beginners.
I'd highly recommend the book
Reef Aquarium Fishes by Scott Michael as a great guide to fish compatability with corals and other inverts. It also gives info on tank size, feeding info and how well the species ajust to aquarium life.