We always celebrate our Anniversaries at WDW, espically since WDW was the second half of our honeymoon
First of all, when making your resort reservation or dining reservations, tell them it is your wedding anniversary. It does not gurantee that they will do anything, but it does not hurt. Last year we were upgraded to teh Victorian Suite at the GF for our Anniversary. The CM's sent us an Anniversary certificate and signed pics of Cinderella and Prince Charming.
I order flowers from the WDW florist. I have to say the flowers are spectacular. They are fresh, and just stunning. I have a beautiful Mickey Mouse vase as a keepsake from an arrangement last year. The flowers that it came in cost $85. I know it sounds like a lot, but I have never seen a bigger more colorful arrangement. It must have been almost 4 feet tall! The vase is so nice to have, my DH fills it up with flowers for me.
If you love seafood, I would recommend Blue Zoo in the Dolphin. I am a seafood lover and am used to fresh seafood (living on an island and all) and Fulton's was less than OK. It's also more of a family restaurant. Blue Zoo is more adult and it would be a much more memorable meal. Victoria and Alberts needs no explanation, it would be fabulous. We go often, but sometimes, I just don't feel like packing the extra clothes to go there. Citrico's is another great choice for dining. We go every trip and it is wonderful, both food and service! Another good choice is Cali Grill.....but not during Wishes. Go during the sunset.....believe me....it is beyond words. Not only is the restaurant quiet, but the sunset views from up there are just sooooo beautiful and they last a long time. My DH and I had a very romantic dinner there last year. We held hands sipped wine and watched the sun go down in a peaceful restaurant. ALso Citricos, Blue Zoo and Cali grill has a dress code of Business casual....easier packing. The GF also has Mizner's, which is a great place to go after dinner.
Last year my DH ordered champagne, drew me a bubble bath with stuff he bought at the GF Spa. I wnet into the tub with the bottle of champagne and the TV remote

and he said he would be back in a little while. I didn't know it but he went out shopping and he bought me presents. He bought me a beautiful snowglobe (minie and mickey on a red heart) and a diamond tennis bracelet....the diamonds are set in little mickey heads. We had a lovely evening at V&A's after that.
There are so many things you can do....couples massage at the spa, champagne and strawberries, private dining - actually you can have a private dinner anywhere you would like. You can do a wishes cruise and you can have the boat all to yourself and you can also have an anniversary cake on the boat. I love going to the evening EMH at the MK and staying till closing. The parks is empty and it's kinda spooky and romantic at the same time.
There's lots to do!