I actually keep a list of things we do. We usually stay ay AKV where there are lots of activities (many free including a wonderful culinary tour, and so many kids activities). We also enjoy heading to Ft Wilderness for a day or two of activities there.
Here is a list I reference (since I tend to forget):
Motor boat rentals (various resorts, but we usually go to WL)
Canoe rentals (Ft Wilderness)
Biking (Ft Wilderness, or WL and bike over to FW)
Segway tours (FW)
Campfire/Movie program (Ft Wilderness)
Nighttime programs at AKV (or other lodges)
Electrical water pageant (various locations)
Fireworks from BLT
Fishing (Ft Wilderness)
Carriage rides (Ft wilderness)
Wagon Rides (Ft Wilderness) Also, a fireworks wagon ride
Pirate Adventure (Grand Floridian is my kids favorite)
Tea Party (Grand Floridian)
Surrey Bike (WL or FW)
Horseback riding (FW)
Archery (FW)
Pony rides (FW)

Excellent list. So many great ones.
Marshmallows at the campfires, perfect!
Fort Wilderness is big for me. Even just the WL/CR/FW smaller boat, that makes me so happy.
I will add some of my lazier options

to that wonderful list:
*Water parks if you have extras left over on your tickets
* expanding on AKL - night goggles - so many interesting activities
* culinary tours AKL
*anything on the BW - I enjoy getting an airplane bottle at the store there and a bottle of coke and mix. Voila! Rum and coke. And the magicians are hysterical
*if you love taking pictures - just a day/afternoon/evening of taking pictures is lovely
* don't forget Hurricane Hanna's is not only for SAB visitors. Nice place to sit and hang and play cards. (Although I do enjoy jumping in and out)
* and the tables by Beaches and Cream are great for hanging out, playing cards, people watching
*the GF has the best terrace (pool side) - it's a designated smoking terrace (or was) but I've read there/hung out and not had any smoking
*WL has many private feeling terraces
*Polynesian beach - fireworks - this is probably wrong but I've read in a hammock there and witnessed a couple of weddings
*some of the resorts have great games rooms
*hanging out on the FW porch rocking chairs - especially great when the bar window is open
*And it's fun to see the actors/actresses getting ready to bang the doors and enter for Hoop Dee Doo - interesting perspective
*Trail's End's buffet used to be available on takeout (they NEVER advertised it but did offer it - using past tense because I haven't done it for awhile) and we used to regularly take one down to the marina to eat - lovely area to eat -they give you so many containers for one buffet order that it fed two easily - they gave you everything needed
*WL and AKV are excellent resorts to hang out IMO - just love hanging out especially if I'm in a
DVC one bedroom
*no better than sitting on the balcony in a BW view BWV room
*or those beloved OKW balconies - LOVE!!!!!!!

*DD is wonderful to people watch and eating free chocolate - what could be better than free chocolate?

- I'm beginning to sound a little off with all this people watching

oh well.

*tour the models at SSR if a new DVC is there
*I love the outside section of Captain Cook's (Polynesian CS)
*the CS at GF is 24 hours and they have an EXCELLENT shrimp stir fry!
*FW has all kinds of rentals/equipment - bball hoops in some loops
*so many tennis courts.
*I enjoy sitting/eating at Pop Century because it's bright and happy (but apparently the CS has had some awful changes - so maybe will be Art of Animation now) and simply reading the paper at an outside table
*love taking the boat up to POR from DD and DD to OKW.
*House of Blues has a very inexpensive Happy Hour.
* walking trails - DD to OKW and WL to FW
Just simply being.

So many people have no idea how wonderful WDW is for simply hanging out! The joy of DVC. One can be as lazy or as active as you want.