Not so sure about "remastering" - especially those old black and white films. The "director's cut" (extended versions), maybe.

As an example, "The Third Man" would be much diminished without those atmospheric shadows; sometimes you cannot see Harry Lime's (Orson Welles') face at all, but rather almost just a
suggestion that he's standing there. Pure art.
Also look out for "Sergeant York" (1941) (Gary Cooper). And "Paths of Glory" (1957) (Kirk Douglas); both filmed in B&W, of course.