I really enjoy keeping wrasses. There are some beautiful fairy wrasses, coming in every color imaginable. If you are okay spending a little more, I really like flame wrasses and mystery wrasses. They are pricey, but awesome fish.
I had a foxface at one time, but he wasn't my favorite. Most of the day he chose to be a grayish brown instead of yellow. I got him from another reefer, so he was pretty big and probably wasn't too happy in my 90G. I removed him with a trap and gave him to a local reefer with a larger tank. The fox was a peaceful fish and ate well, but not much to look at.
If you are looking at tangs, you could put a yellow in there or you could try a purple as well. My purple tang is my favorite fish. I prefer both of those to the kole, but that's just me.
It's a risk, but I've had good luck with dwarf angels. I've kept a coral beauty and a flame angel - neither one bothered my corals and they are great fish with lots of personality. Flames are stunning.
My favorite fish is my copperband butterfly. I got one to battle an aiptasia problem, and it did the trick. It probably ate 50 aiptasias over a week or so. They are tricky to get eating, but if you get one that will eat at the store you should be fine. Mine eats mysis like a champ. Established tangs (especially yellows) will make adding a CBB difficult. My purple tang was added at the time as my CBB and they get along fine.
Good luck.
