I work with animals, so pretty much all animals I like; I find them fascinating. But ever since I was little I had an obsession with large carnivores like big cats and crocodiles. I didn't actually start liking dogs and other canids until I was in my early teens - up until then, I was kind of scared of them. Even my neighbour's Jack Russell terrier. I'm also quite fond of cattle and chickens for some reason... Must have been those three years I spent on a farm.
So I can't really call out a favourite. xD All I can say is give me any animal except an invertebrate or a primate.