"the Best" is as good as others, but is it as good as it can be?

"at risk" means the title could be unqualified thus removed, WIP

4K Blu-ray discs with the best A/V quality up to date. Typically, they are considered definitive or "Endgame" versions that seemingly need no more improvements. They must be as close as possible to the picture and sound mix the film was originally released. Mainly older titles either entirely shot on film and released from 1930 to 2001. Some post 2001 titles could qualify as well?