Howdy Jasmine!! Thanks so much for your question!!
I have gone back and forth on this. Both resorts are fantastic and both offer wonderful amenities. I think either resort will provide you with a great backdrop for a magical vacation!
Since I need to pick just one, based on the ages of your children, I think your best option would be
Disney's Saratoga Springs Resort and Spa.
The resort is fantastic and is within walking distance or a short boat ride to Downtown Disney.
There are nightly campfires, a great community hall where you can enjoy things including video games, crafts and games such as ping-pong and foosball. There are also a variety of playgrounds, surrey bike rentals and 5 pools!!
If you select Saratoga Springs for your vacation, you might request that you have a villa near the Paddock area. The Paddock Pool is incredible! It has a 146-foot-long waterslide that is amazing and a zero-entry area for your three year old.
We love the resort! Like all of the DVC resorts, Saratoga Springs is wonderful! There are several great areas for some amazing photo opportunities! You will love taking pictures of your little ones as they make magical memories!
Both Old Key West and Saratoga Springs are our home resorts so please let me know if you have any other questions about either resort. Thanks again for your question and have a magical day!