I agree that Chef Mickey's is a must-do. However, just to give you another perspective, we chose the Rainforest Cafe for our son's 4th bday lunch. Here's why: We always go to Chef Mickey's on our arrival day, and this trip was no exception. Our son's bday was a couple of days later, so we'd already been there. Secondly, our son adores animals. We chose the AK on his bday because he loves them so, and we had animal themed presents, decorations and cupcakes that I brought with us back in the room. Third, we have a Rainforest Cafe here, and he loves it. He's only ever been twice, and he asks to go often.......we know the menu, too, so we know we like the food...........we like Chef Mickey's atmosphere, but we like the food at RFC better. Finally, I'd just like to let you know that we told them it was his bday, and they asked if we'd like for them to bring him out a bday treat (don't know what it would've been), but I told them we'd already planned to get him a volcano. A volcano is two scoops of ice cream, surrounded by four giant slices of chocolate cake with chocolate icing, and chocolate syrup all over the thing. There's a sparkly topper on it (used to use real sparklers a while back, but I knew that wouldn't last!). Anyway, they brought it out, WITH candles, which they lighted and had him blow out, and all the servers surrounded him and clapped and sang for him. He loved the attention, he got to blow out candles on his bday (I had brought the cupcakes with us for this express purpose), he got this TREMENDOUS-sized dessert, very special, not like cupcakes which are nice, but not so EXCITING.
So, if I did another bday at Disney, and those were my choices, again, because we already do Chef Mickey's traditionally, because kids love the animals and fish tanks at RFC, because we like the food, and because of our last experience there, I'd choose RFC.