I get sad when I kill a fish because it sucks to take a life through carelessness or something you can avoid. I don't name fish, but I let my wife / coworkers do it if they want.
Bill murray the black occelaris (who has since become female)
Eduardo the orange perc (Bill's gay lover)
Waldo the sexy shrimp (in a 55g)
Dot matrix the royal gramma
Chaoti wrasse (still deciding between wrassy pants, Cardinal Wrassinger, Wrasseputin, and a couple others. Wrasses are such a goldmine to name).
Dumbledore the green mandarin (for his epic fashion sense)
Flounder the maroon clown (girl at work named him)
Knock it off you A$$hole (maroon clown at home I constantly have problems with)
Fred and George (identical yellowtail damsels, until fred tried to kill george and I had to separate them)Oh yeah, and crabby patty the emerald.
Everyone else just gets the honorific -butt after their name. Goby-butt, cleaner-butt, urchin-butt etc.
Edit: Technically, eduardo is edward II since edward I jumped to his death and that is why I have eggcrate over all of my tanks now. I was sad and so was bill (