Seen it mentioned above that the transition from DVD to Blu-ray is as significant as VHS to DVD was – it isn’t.
Saying that, it is definitely worth it when set up correctly. The Dark Knight and Iron Man are both good recommendations – Planet Earth is simply stunning.
As an aside, for anyone with just Sky HD, Die Hard 4.0 is quite possibly one of the best pictures I’ve seen on my screen.
As for HD sound – pre HD codecs, DTS had the edge over Dolby Digital – I’ve not yet decided my preference between Dolby HD, or DTS Master Audio, but they are both stunningly good – saying that mine outputs via a quality Yamaha AV Amp and a dedicated KEF AV speaker system.