My DD turned 5 on Saturday. Thanks to this thread, I think we got every magical bday experience offered! Here's what we did.
Before the trip, I made sure that her bday was noted on our room ressie and our PS's at the Perfectly Princess Tea party (for Friday, since they don't have it on Saturday), breakfast at CRT, and dinner at Chef Mickey's. I mentioned her birthday again when we checked in, and it's a good thing I did. I watched the CM write the date and her favorite character down, so I figured *something* would come our way. I doubt anything would have happened had I not said something at check-in, though.
Each time I dropped the hint, I was careful to engage the CMs in conversation first and then casually mention why we were at WDW (without DH and DS), not just say, "It's DD's bday, so please give her something." Not that any of us would actually say that, but as a former CM, I know that attitudes like that get old fast.
I think it also helped that DD was feeling very outgoing this trip. She spoke with each CM who engaged her in conversation, and her excitement about turning 5 seemed to be infectious.
Although I made her a t-shirt with an iron-on proclaiming it to be her bday and she was wearing 3 bday buttons from MK and Epcot, I learned not to rely on those to get the CMs' attention. They see so many people each day, that sometimes they fail to notice the visual cues. For example DD spoke with Ariel for quite a while, but Ariel failed to see her bday shirt/buttons until DD came out and told her it was her birthday. (Appropriate fussing and oohs and ahs ensued.)
Finally, I tried to schedule the earliest possible PSs for all of our special meals. I knew the servers and characters would probably be at their freshest and most enthusiastic.
We enjoyed the most special attention at the more unusual places to celebrate kids' bdays. The tea party, although absolutely wonderful, was the site for multiple Princess birthdays. We sang Happy Birthday as a group, but no one knew who the birthday girls were. CRT was also very nice, with table decorations, an excellent mini birthday cake and some bday wishes from our server and the princesses. Chef Mickey's celebrated everybody's special occasions as a group, with the Celebrate song, but she did get her own cupcake and candle with Minnie there to witness. We got the birthday placemats at both CRT and Chef Mickey's. Very nice moments all, but kind of expected and not as "magical" as some of our other moments.
She got the most special attention at Everything Pop, Main Street USA, and Le Cellier. At Everything Pop merchandise, a CM noticed her Aurora costume. DD talked with her a while and mentioned that the next day was her birthday. She wanted to do a pin trade, but the CM just gave it to her instead of trading. Then the CM had Goofy sing Happy Birthday to her on the phone and gave her a Magical Moments certificate signed by Goofy. In the food court, another CM DD spoke with learned it was her bday and sang to her in Spanish.
The best was dinner at Le Cellier. When we checked in (at 4:10!), I mentioned that her birthday was the next day and that she had chosen this restaurant because she loved the chocoalte moose last time. She ended up becoming a "Jr Chef" and getting to assemble her own moose, with the help of Chef David. She also got a birthday card from the entire staff.
On her actual birthday morning, we were walking down Main Street to get to our 8:05 CRT PS. There was a group of CMs in training of some sort. One of the group leaders noticed her Cinderella costume and started talking to her. Of course DD mentioned that it was her bday, so the CM told her that she had some royal subjects here and had the whole group (25 or so) sing to her! She also gave her a pin from her lanyard without trading for it.
As we settled in for our nap that afternoon, I mentally patted myself on the back, reflected on our good luck, and thanked this board for all of the great ideas. After basking in the feeling of being the "Bestest mommy in the whole entire world" (her words, not mine), I heard a knock on the door. DD was still asleep, but when she woke up, she saw the balloons and autographed photo card of Cinderella that Pop Century had provided.
The only downside of all this was DD asking me, "Is my birthday ruined now forever?" Yes, I guess she's peaked at the ripe old age of 5.