Land: Tiger, nothing is as strong and as powerful while still silent as a supa ninja and able to be shot in head from three feet away unphased.
Air: Hummingbird, it's wings beat in a figure eight, it can fly upside-down, bacwarrds, sideways, and in place.
Sea: Killer Whale, one of the only animals to have killed and eaten the infamous Southern elephant seal and legendary great white shark, both at adult size.
Best Sea animal- Dolphin (they are intelligent and have complex social systems) Best Air Animal- Hawk (Who wouldn't want to be the biggest, baddest cat in the sky?) Best Land Animal- Tiger (The feline that can kill you in water and out, and still make it BA either way)
Wolf (first one to say wolf without the wolf armatar) --High stamina, pack mentality, two can handle a grizzly. Giant Freshwater Stingray --Unbelievably huge, a glancing blow of its stinger gives enough poison to cause excrusciating pain for weeks and make you unable to do work for six months, a direct stab is lethal. Peregrine Falcon --200 mph, need I say more?
Land- It is hard to decide, I don't know if I choose a wolf or a tiger, they are both awesome. But I chose wolf because the tigers will be extinct in this century.
Sea- Shark. I don't see any other awesome animal in the water as a shark.
Air- Peregrine Falcon, as Dragonblaze said. It is very small but it gets really fast and it is a beautiful bird.
I really like wolves. They're intelligent, and their secret agents have infiltrated our households (Dogs). I've always been partial to foxes as well, though I don't really have a reason for that. Because they're cunning, I suppose. I also like falcons. They impress me with their speed. :P As for water, I'd have to say either dolphins or seals.
As for Antarctica, It's definitely penguins, since I am one.