I have kept many types of dwarf angels (Centropyge sp.) in my reef tanks over the years. While I love their color and active behavior, they also have their drawbacks.
Most of them picked at coral or, despite their, size were relatively aggressive. In particular I had an issue with Flame Angels. They seemed to love destroying my red Trachyphyllia brains. Most other corals were simply nipped at causing less polyp extension.
For my 120-gallon aquarium, I wanted to find an angelfish that was going to be actually reef safe (i.e. less aggressive and wouldn't pick at corals).
I began researching and asking other hobbyists what their experiences have been and if they had any recommendations for a reef safe angelfish. I discovered most feel there is no such thing as a reef safe angel. The closest are Genicanthus angels. There are 4-5 different Genicanthus angels readily available to the trade, including the Lamarck's angel (my choice), Swallowtail angel, Wantanbei angel, Bellus angel and Zebra angel.
Besides the reef safe factor, there were two other characteristics that drew me to these angels. First is their color. All are predominately blue, which just so happens to be one of my favorites colors. The second is that you can keep a pair in your tank. The differences between males and females are easy to identify, some being very different.
To find out more, I posed a question to Dr. Frank Marini about the angels on the Marine Depot Forums. He let me know that "Many Pomacanthidae are sequential hermaphrodites, and Lamarck angels are similar. With the fish determining as a female first -> then transitioning to a male when needed (termed protogynous.)".
I presently have a single Lamarck angel in my tank—a model citizen so far—and will eventually add a second in hopes of pairing them.
If you are looking for a reef safe angel for your tank, don't overlook the Genicanthus angels!