My favorite Disney movie has been The Little Mermaid for years, and it remains my favorite Disney musical. However, Up works on so many levels I must enthusiastically recommend it to anyone looking for an excellent film.
This film deals with friendship, love, grief, loss, disappointment, anger, jealousy, aging, courage, adventure... in a format that appeals to all ages.
I loved the way that the villain's minions (dogs) were presented as both terrifying and with natural flaws/weaknesses. It made the escapes more believable.
Pixar's images were stunning as always. But the best part of this movie is the plot, the characters, and the changes they go through as they grow. This really does deserve the rumored Best Picture Oscar.