I've always been a fan of dolphins, with their 98% gray matter/brain ration, and there concomitant language abilities. I also like the newly rediscovered prehistoric beasts, whether under the sea still alive or under the tundra perfectly preserved. But my favorite of all time: The unicorn.
I have to admit that I, and I'm sure many others, have an affinity for the large felines. I think I might go with black panther.