I'm guessing the rarest DVD I have is a german region 2 Back to the Future set that has been released before the US Back to the Future DVD collection.
It has less special features than the US version unfortunatley.

And probably also that worthless (but now rare) Wal-Mart "The Story of Star Wars" DVD you get after buying Episode III...

we're talking rarity right? Because I don't like those two DVDs I mentioned and I find my three LOTR movies (the EEs) alot cooler looking
and awesomly designed.