There are lots of things to do in the evenings at WDW without going into a main park.
You can check into your resort and take a swim in the pool.
Get a PS for a character meal to get you in the mood.
Stroll through DTD and make sure to take the kids to the newly renovated and just opened
Lego shop.
Catch a movie at the AMC 24 Complex at DTD WestSide.
Play miniature golf at either Winter/Summerland or Fantasia Gardens
Go to Disney Quest
Go down to Boardwalk and walk around, grabbing a slice of pizza and play carnival games.
Rent a surrey bike.
Go to a dinner show like Hoop de Doo Review or Spirit of Aloha Luau
Go to Fort Wilderness for the Chip and Dale sing along and Disney full length feature movie.
Go to one of the monorail resorts and hop on the monorail and ride.
See Cirque du Soleil La Nouba
Stop by Port Orleans Riverside and catch the piano player in the lounge.