For me I like #2, it looks more professional, clean, easy to read, and the colors are more pleasing to me. The only thing I might add is some small graphics of a mouse, cat, and the lizard or something on the back, similar in size to the fish bowl, dog house, and bird cage. Maybe put the animal graphics on the front, and put the house, cage, and bowl on the back???
For me the other two are just way to busy, and it's really hard to distinguish between the swirly brush, and animal graphics on #1, and the colors on #3 look a little school-like, as if they were just pulled out of the Crayola box. I just really like #2, it's pretty cool, very warm, and inviting with the color tone.