The full name of this coffee place is Dr. Bombay's Underwater Tea Party. They sell chocolate and white chocolate handlebar mustaches on sticks. I'm sort of fascinated with it right now. They are so hardcore in their approach to whimsy that it becomes surrealist. They also serve ice cream. It's in Candler Park, naturally.
Atlanta has a few so-odd-it-might-actually-have-been-a-dream coffee shops but this one tops even ParkGrounds in Reynoldstown, which is a coffee shop with a patio that opens onto a dog park. It's a strange place to get coffee, especially when you don't have a dog, but it's also a pretty great idea.
Then there's Joe's near the EARL. They have a secret garden in back with a goldfish pond. But, right now, Dr. Bombay's is queen of my heart.