Gizmo, the maroon clown (Premnas biaculeatus). At 10 plus years old, this one is the oldest fish in my tank. A member of the damsel family, she is no 'Nemo'. She is about 5" long and lives to eat. She will harrass new fish and has probably starved out 4 Pearlscale Butterflys. She likes to be around aiptasia (and any anemone really), but that has been the only anemone that can survive around her.
  
When I got this little butterfly it was smaller than a 50 cent piece, but not it is close to 3 inches long. She (he?) didn't get along with my maroon clown so, I would spot feed her after she cleaned out most of the aiptasia until she got big enough to compete with the other two for food. She keeps the aquarium 'aiptasia free' except for a small patch the maroon is guarding.
The yellow tang is the second one I have had in the tank and it has a different personality than the first (more agressive). At this point there is no one she can pick on really. I believe they are called surgeon fish because of their barbs near the tail. Fortunately she hasn't gone after the other fish in my tank
I have a lobster somewhere. I see when it has molted occasionally, but it never comes out of the rocks when the lights are on. If I can ever get a picture, I will post it here
I don't know the names of some of these, so this is just a few pictures