my ocellaris clowns are super peaceful and never have I seen them getting picked on or picking on anything else in my tank... and that's a small 14G tank too. I believe the clarkii's are pretty aggressive....
Anything is nicer than a maroon. I think the rest are about the same. But occelaris are the most peacful, my clowns are so sweet I got kinda worried that they wern't being aggressive towards my other fish or shrimps!