Hi Ngoc:
You are traveling to Disney World at a perfect time, January, when crowds tend to be lighter because schools are back in session.
For convenience and fun, I would strongly consider
Wilderness Lodge, a Resort inspired by the Great American Northwest National Park lodges from the turn of the 20th century. Wilderness Lodge is located near Magic Kingdom and is accessible to that Park by a quick and relaxing boat ride that the kids and seniors may really enjoy. Another option is to stay at a Resort right on the monorail, which provides quick and convenient access to Magic Kingdom and Epcot. In particular, the
Polynesian may be considered the most "fun" of the three (its got a tropical feel and a fun pool with a volcano). Another option may be a Resort in the Boardwalk area, which provides quick access to Epcot and boat access to Hollywood Studios. Specifically, I would look at
Yacht or
Beach Club Resorts as few people will disagree that Stormalong Bay (shared by the Yacht and Beach Club Resorts) is the best pool on property with a major water slide, several sections, and a lazy river. Your boys may really enjoy that pool.
If you are looking at a Value Resort,
Pop Century is currently considered to have the best themeing.
Enjoy your vacation.