I think Blu-Ray is best used for movies that feature intense color and/or plenty of action (explosions, fast camera movement like car chases, etc.). While there's improvement in most conversions to Blu-Ray, I think you get the most bang for your money in those scenarios. The other place I've found it to be worth the value is buying television shows. Dr. Who, Torchwood and Downton Abbey all look fantastic on this medium.