Rainforest Cafe' over Planet Hollywood any day. Better atmosphere and better food.
The Rainforest Cafe' at Downtown Disney is nice but crowded. If you can go to the one outside of the Animal Kingdom, it is much better. Plus, the outside waterfall is amazing. You don't have to have a park ticket to get to the Rainforest cafe' at the AK because it is outside of the gate. But, you can use WDW transportation to get you there and back!