I think most of the common suggestions have been made. Gobies, Blennies, Wrasses, Clown Fish (Osc or Perc varieties prob best). I really like my Cardinal but they are not very exciting for some first fish. Banghai same thing but what is good is they will stay out in the open, generally, where was some of the others will tend to hide by nature. Also many of the Gobies, Bleenies and Wrasses will jump, so you will need to seal off jumping routes. The 'Tang Police' will say no tangs but I think you could buy a small Fox Face and be fine for quite a while. Pygmy Angels, Coral Beauty and Flame Angel, not the biggest ones. Just go to Drs Foster and Smith and follow the Live Aquaria link for many pix. HTH
Bill