300 - apparently looks amazing on cinema screen, i watched a pirate version of it so i don't really know. Hero - In my opinion is one of the most visuallly attractive films , i have ever seen.
may sound strange but when you go and buy a new cinema system here they are always showing "finding nemo" they say because of the colours its the best film to show
Since we don't know what format your buying, blue ray or other, then there's no way to decide on a film because blue ray technology doesn't have that many movies on it as yet. There are some, that's why you have to see what's available.