I just posted many of these suggestions on another post, so forgive me if you read hers too. I just wanted to be sure to answer to you directly, since I LOVE a good adult Disney trip!!
Here are some experiences I recommend:
1. Savor, Sip, & Sparkle, Celebration at the Top (this is at California Grill in the Contemporary) - we do this on nearly every trip to Disney World now. The food is great, the cast members treat us like gold, and I think it is a great value!
2. How about a fireworks cruise? We have always found this a great way to celebrate a special event.
3. We love doing a Monorail Drink-a-Thon (Disney has an official one, but we are kinda partial to the unofficial version we found online.) There is a company for FUNatics who sells personalized passports for really cheap (you can google it or send me a PM) - the passports outline a fun excursion where you visit each resort on the monorail line (and the two resorts accessible to the monorail line via boat for "extra credit") and go to one of the lounges/bars/restaurants for beverages and snacks. Super fun - we do this every trip now.
4. The Wilderness Back Trail Adventure tour on Segways is super fun.
5. Drink Around the World Showcase (the same company from the Monorail Drink-a-Thon has personalized passports for Epcot's World Showcase (Monorial Drink-a-Thon and Showcase Snacking) for drinking and eating around the World Showcase. We do this every trip too. Take some time to enjoy La Cava Tequila for the best margaritas and the Tutto Gusto wine bar in Italy is another great place to relax, enjoy some wine, and have a snack.
6. I second Jellyrolls - super fun for an evening after the parks.
7. Since will be there during the Food and Wine Festival, try Party for the Senses if you can swing it; it is OAMAZING! Tons of stations of food, wine, beer, and mixed drinks, with just crazy good entertainment.
8. Also, during the Food & Wine Festival - we LOVED the meal at LaHacienda in Epcot where they had a several course meal paired with tequila - the tequila ambassadors are wonderful, the meal is wonderful, and the tequila helped me realize I like good tequila!
9. Other Food & Wine events we have enjoyed: the little classes that teach you how to make drinks or make a food item, the wine tasting classes, and some of the free courses in the Festival Center.
10. Visit Disney Springs - there are so many new places there! Our passport place also has a personalized passport called Sippin' and Snackin' in the the Springs, which is another fun excursion to try beverages and snacks in different places in Disney Springs.
Have so much fun!!