If you're lucky enough to already own a bluray player and a High-Def television, then I'd highly suggest purchasing this. I haven't seen the DVD, so I can't comment, but the blu-ray disc is nothing less than stunning.
Planet Earth is an Emmy Award and Peabody Award-winning BBC nature documentary series narrated by David Attenborough and produced by Alastair Fothergill. It was first broadcast in the UK from 5 March 2006. The American version is narrated by Sigourney Weaver.
The series was co-produced with Discovery Channel and the NHK in association with the CBC, and was described by its makers as "the definitive look at the diversity of our planet". It was also the first of its kind to be filmed entirely in high-definition. The series was nominated for the Pioneer Audience Award for Best Programme at the 2007 BAFTA TV awards.