I've never been good at naming pets. My cat and chameleon were named by the people who gave them to me, but I came up with a couple names for my more outstanding fish.
Angelfish: one named Lucifer, one named Jesus (Spanish pronunciation)
Rainbow Shark: Hardy - he's a survivor through two leaking tanks and the temporary housing transfers that killed the other two fish I started with
Zebra Danios: won't hold still long enough to get a name
Male Cherry Barbs: big one - Mac; small one - Soltaire (he's kind of a loner)
Female Cherry Barbs: Pregnant looking one - Mama; other two unnamed
Pleco: Al - named after my buddy, Al and also short for Algae
Gourammis: trying to think of a cool trio to name them after