I tend to go with either previous RL pet names, my cats were for a long time called Noggin (pet cat when I was about 2 was named after the cartoon of the time Noggin the Nog). But more often than not I go with famous philosophers names: Nietzsche, Dostoevsky and Plato are favorites.

If you give them all the same name, addons that report stats to the screen (omen, ktm, parrot, etc) Treat the pet as a single unit, makes it easy to work out how much threat it has but the game knows so you can still see what is going on...