There are three things that keep the charm and magic of this Disney classic alive: the music, the characters, and the animation. It's as simple as that.
With toe-tappingly addictive tracks like "I Wanna Be Like You" and "Bare Necessities", the musical numbers are an obvious highlight. This is primarily a credit to the voice actors, who also act as the driving force that make the abundance of characters such a treat. Baloo, a fun-loving laidback bear who befriends Mowgli (voiced by the perfectly cast Phil Harris), is easily the most beloved of the bunch, with the mischievous Kaa (a python with a penchant for hypnotizing his prey) and the unruly King Louie (an orangutan who desires the secret of making fire) coming in right behind him. Tying this all together is the lush animation, which adds an amazing amount of personality and humor to the film. It occasionally looks a little rough around the edges, but that gives it a personal touch a lot of animated pictures could benefit from; that is, if they even made real animated pictures anymore (CGI films excluded).
If I have one gripe with THE JUNGLE BOOK, it's that its second half isn't as fun as its first. Baloo drops out of the film briefly, and characters like the goofy vultures (stylized to look like British rock singers) aren't enough to make up for his absence. This is a minor issue though; one that barely constitutes as a problem since most young kids don't even finish the films they start. And with the rest of the movie being so joyously entertaining, adults aren't likely to care either.
Audio Commentary (with Richard Sherman, Andreas Deja, and Bruce Reitherman): This retrospective track offers a lot of interesting information and insight into the film, but it all comes from very odd perspectives. Richard Sherman worked on many of the film's songs, Andreas Deja is the supervising pencil animator at Disney, and Bruce Reitherman is the son of the director and voice of Mowgli.
The Lost Character: Rocky the Rhino (6:35): Much more than just a deleted scene, this brief but still in-depth featurette gives an extremely worthwhile look at one of the characters that never made it past the storyboard stage.
Deleted Songs (21:00): Available here are seven "audio only" tracks that never made it into the film.
Disney Song Selection: This easy-access scene selection allows for kids to quickly hop to their favorite musical number from the film.
Also included is a piece about the Disney Wildlife Conservation Fund, as well as a Music Video entitled "I Wan'na Be Like You", performed by the teenage rock band the Jonas Brothers, and a vast amount of Sneak Peeks. I'm ashamed to say I actually liked the music video.
The Bare Necessities: The Making of The Jungle Book (46:23): A wonderfully in-depth 5-part featurette that provides every aspect of possible interest in the making of the film. Both old and new interviews have been included, ranging from such topics as the voice work, the music, and Walt Disney's overview of the production.
Disney's Kipling: Walt's Magic Touch on a Literary Classic (15:00): This slightly shorter but still fascinating mini-documentary looks at the transformation from novel to film.
The Lure of The Jungle Book (9:25): A retrospective featurette with the Disney animators offering up their thoughts and stories about the film.
Mowgli's Return to the Wild (5:10): An interesting look at the director's son, Bruce Reitherman, whose voice work as Mowgli kick-started his film career.
Frank & Ollie (3:45): A vintage interview with two of THE JUNGLE BOOK's main animators.
Baloo's Virtual Swingin' Jungle Cruise: A 4-part virtual DVD game for kids.
DisneyPedia: Junglemania! (14:19): A terrific featurette for kids that allows them to learn more about the animals featured in the film.
The Jungle Book Fun with Language Games: A couple more games for kids (in this case, allowing them to identify jungle animals), this should be fun strictly for those of a very young age.
There are also six Art Galleries.
Miscellaneous: Lastly, there's a handy trifold mini-guide to the DVD.