1. Wreck-It-Ralph
If theres anything Id consider a dead cert for inclusion in Kingdom Hearts III, itd be Wreck-It-Ralph, the 52nd and most recent addition to the Disney Animation Studios canon. Why? Because the focus of the film was on video games, and what is Kingdom Hearts? Exactly. Sora even had a brief cameo in the film, though he is very, very difficult to spot. Featuring a character that travels through an assortment of gaming worlds, Wreck-It-Ralph contains both sci-fi action sequences and kart races, both of which would be fun additions to the Kingdom Hearts universe, whilst a playable version of Fix-It-Felix Jr., the fictional game that Ralph is originally from, would make for an interesting timewaster. One of the best parts of the film was its constant homages to classic games, including both a homeless Q-Bert and graffiti tags that read All your base are belong to us and Aeris lives. Similar references in a Wreck-It-Ralph world wouldnt go amiss, giving gamers a number of Easter eggs to find.
Ending on a footnote, Disney has international distribution rights for the films of Studio Ghibli, the Japanese animation studio responsible for the works of Hayao Miyazaki (such as Ponyo, Spirited Away and My Neighbour Totoro). Not being familiar with these (criminal, I know), Im not really in a position to write about their possible inclusion in the Kingdom Hearts series, but feel free to discuss the matter (and anything else) in the comments section.