Easily the best film I've seen this year, Happy Feet glides on the ice with amazing spec fic sensibilities, a moving theme, excellent characterization and voice acting, dazzling animation and must-buy-the-OST music.
Director George Miller adds Happy Feet to Babe in terms of exploring various things that make us human through the POV of animated animals. I applaud the use of the "humans as aliens" scifi trope to underscore a serious eco message (which, surprisingly, does not burden the film). The narrative moves along nicely, insterspersed with song and dance numbers that make me want to clap my flippers above my head like the penguins.
My only criticism was the somewhat "merely competent" ending (well, that and the fact that we nearly froze to death in the moviehouse - but that's not the film's fault, though perhaps we oversympathized with the movie environment). Other than that, it knocks "The Prestige" off the number one slot.
Go and see it.