Our last trip was a resort and DTD only trip. We spent this trip at VWL to relax and headed over to DTD in the evening. We had plenty to do, including 1 visit to Disney Quest and a few evenings at Pleasure Island, including the Comedy Warehouse and the Adventurers Club. We were not at a loss for things to do with all that DTD has to offer coupled with resort activities and exploration of Fort Wilderness. But each resort will have its own fun.
I would definitley recommend a DTD/resort-only trip if you are in the mood for more relaxation and a slower pace. There is plenty to do at each resort. Saving the price of park entrance was nice, too. Practically a free trip. Other things to do in DTD include: running through the fountain, visiting the birds outside Rainforest Cafe, Magic Masters shop, World of Disney, great restaurants, House of Blues store, HOB concerts (sometimes outdoor entertainment), boat rides to resorts, fireworks (however brief) at midnight, Cirque, AMC theatre, people watching, great views, and a lot of walking. If you haven't been to Wolfgang Pucks, they have great food and, if the weather is nice, there is nothing like an outdoor seat in the evening and a view of the lake and SSR.
All that said, we are going back again and looking forward to the parks this time.