Elephants used to be my favorite animal. I think the concept of "Favorite Animal" is kind of silly, especially when your favorite animal is one that you've never actually interacted with. Even if your favorite animal is a cat or a dog, some kind of animal that you've met plenty of, how do you know that you wouldn't like a wombat or a an anteater better, given the opportunity to hang out with one? That's silly, you might say, because we pick our favorite animal based on the animals we are aware of, just like we pick our favorite song from all the songs we've ever heard.
I realize this is a purely semantic argument that has no satisfying conclusion.
Anycrap, my favorite animals are monkeys. Now, I'm not a scientist, so when I say monkeys I refer to the 264 known extant species of monkeys AS WELL AS the two known types of chimps, orangutans, and all non-human apes. All think non-human primate, but mainly it's just more fun to say monkey.