If you want the most amazing Blu-Ray ever, I recommend you get Life (the BBC documentary). Also, order from Amazon so that you can the version narrated by David Attenborough, rather than the one narrated by Oprah (which is what you'll find at Best Buy, Target, etc.). Visually, it is probably the most stunning, jawdropping picture of any Blu-Ray I own. From a content standpoint, you'll find yourself saying "wow" or "amazing" or "how the fuck did they catch that on camera" every handful of minutes.
The BBC really brings their A-game on all of their nature documentaries. I've been gradually collecting all of them and they all are nothing short of fantastic.