Yeah, sadly they are a pain, although people have successfully reared Ambon damsels, which is what I have at the moment. It's just hard because they're so territorial and it's quite difficult to tell the sexes apart without freaking them out.
Thanks anyway :)
Cutest fish ever is a juvenile cowfish...
Longnose cowfish in Lembeh Strait | Lactoria comuta | Tony Wu's Underwater Photography Blog
...for a bit of size perspective, the juvenile I saw, which was yellow, was 1x1cm.