Do you mean favorite art, or favorite in terms of chance of winning?
For chance of winning, it varies based on what cards have been played.
It's also different in the 4-5-6-7-8 rounds versus the 3-5-7-9-11 rounds. For the 3-5-7-9-11 rounds, you want to get 3 rabbits and then pull from the deck that gives 2 rabbits at a time.
If your opponent has pulled a cat from a deck, now the odds greatly favor that deck. If your opponent pulled rabbits from a deck, now the indication is to stay away.