Great reponses. I ususally pick the most dominant too. But about 5 years ago I needed a female for my male midevil. Well petco had 2(because somebody ordered 3 and only bought 1) and I decided to SAVE the beat up one. Well sure enough SHE healed up perfectly and about a year later I was able to pair her up with my male. Yes it was a lucky guess but sometimes its nice to save a fish. So the moral of my story is it depends on what you need/want at that time.