The best of the series, the first installment (the only with its original director) maintains the separateness of these people without dramatizing it. Its interview-style questioning and matter-of-fact voiceover leaves no room for exaggeration in its structure: it asks each child the same questions and moves on. Allowing them to speak for themselves is not only most respectful to them, but to the filmmaking.
The first film in the Up series is absolutely fascinating. Obviously its the children that really makes this so interesting. Their worldview is absolutely fascinating and practically everything they say is so friggin interesting. A beautiful portrait of a generation! I am so excited to watch the rest of the series.