Well it depends on when you are going! Disney has lots of seasonal events. I am going on my Honeymoon in Oct we are doing the Halloween party and food and wine has alot of events.
I know I would love it if my husband had flowers delivered to the room through Disney Flowist or got a mini cake that looked like our wedding cake.
Too bad he doesn't read the boards. We are also planning on eating at a few signature restaurants.
Other ideas
Pick a pearl; I have really enjoyed the one in Epcot.
Jelly Rolls
Bar/Lounge hopping
We still enjoy playing in the arcade but we're big kids!
Pictures, you could do a photo shoot or do silly ride pics.
Privet dining or room service
Rent chairs or a cabana at the water parks or pool side to relax
Take time to walk the trails in AK and really see the animals
Go to shows, my family never went to the shows we where ride focused so now I am really amazed how many good ones WDW has.
Behind the Seeds Tour, in the land ride and is really affordable.
Take a resort tour, WL and AKL offer free tours of the lobby/resort.
Check and see what activities your resort has and other resorts. AKL does the tour, but also has a wine tasting all year round on Wednesdays I think, and at night you can watch the animals with night vision Google. Lots of the resorts have bon fires at night or show movies outdoors.
I am sure there is more but thats all I got right now, hope your trip is great!
