I currently only have a maroon clown, but he is beautiful. The next thing I will add will be an anemone, but I am also thinking of adding another maroon. Not sure if that would work though, since he has been living in the tank for more than 6 months and may not take kindly to a newcomer.
I have also considered keeping some type of dwarf angel, but I don't think I want to risk it with corals.
I will probably try a blenny of some kind in the future, I like the perching type of fish and they seem to stay out of the way of the clownfish.
Just be aware that clowns can be agressive, especially maroons!
I had a nice lawnmower blenny, but he must have had a stomach bug, because he ate and ate and ate and just stayed so very skinny. Water params were right on, and he just died one day.