I always had a preference toward cats, probably cause I find them amusing. But dogs are also amazing. I love all animals, really. You can form a bond with any creature, so it’s really difficult to make a choice.
Penguins I know there's tons of different penguins, I just love them in general. I know they can be right assholes sometimes, like throwing one into the water to check if there are predators, but I mean, they're cute, super intelligent and almost always mate for life.