[j. d. worthington]

On this one, the best advice I have is: find a reviewer for DVD releases that you trust, someone who does this either out of love for film or for a living, and get their opinion before buying. There are indeed plenty of them that are nothing more than cheapjack marketing tools, but there are still a fair number (especially with older films) where the "Director's Cut" makes substantial changes in the film, often for the better. With older films -- I mean classic films here -- often they were cut down over the years until large portions of the original release have gone missing (Lost Horizon, The Devil and Daniel Webster;aka All That Money Can Buy) and while these are generally labeled "restored" when all that (or what survives of it) is replaced, occasionally they have been labeled "director's cut" for one reason or another ... and this is the only way you'll ever see anything close to the film the way it was envisioned and originally released.

So -- find a knowledgeable source, and let them be your guide; or, where possible, rent the director's cut and compare for yourself.