You will need a region free blu-ray player to view region locked Blu-rays (ie Blu-rays from European or Asian distributors) but some of the best physical media releases are coming from non US distributors. Not all of course, but quite a lot. If you do not own a multiregion Bluray player you are missing out.
Do your own homework but one that works for me (and does 3D) is:
You especiaaly want an all region player to support the ability to play the top of class releases coming out from Blu-ray Distributor INDICATOR.
They make the best boxsets in the business in terms of content and composition. Just beautiful artifacts to watch as well as to adorn finer bookshelves everywhere.
Here are my recommendations for ones to pick up on the current sale before they sell out:
Those are all the box set related special editions that are currently on sale.
Here are the one title limited and standard editions that are currently for sale: