If we are in the mood to spend time on property but outside the parks, we will invariably be drawn to the resorts.  My wife and I are in love with the Disney resorts and never tire of touring them.  A great way to spend some non-park time for us would be to catch a meal at a Boardwalk Resort restaurant, Kouzzina is always a good choice for us.  An evening reservation allows us to then spend time at dusk watching night fall on Crescent Lake.  The atmosphere in the Boardwalk area is truly magical!

In order to fill in some mid-day time, a dip in the pool at your Disney resort (you are staying on-property of course) and then some miniature golf at Fantasia Gardens is a perfectly acceptable way to spend a day at WDW.

Some other suggestions:

1. Rent boats from the Polynesian marina and tour the Seven Seas Lagoon
2. Parasailing
3. Shopping and dining at Downtown Disney
4. Take a DVC presentation – informative, low-key, and interesting
5. Take advantage of resort tours

There are endless things to do outside the parks, all worthwhile, many free, and all are full of Disney magic.