I agree that The Innocents should be seen, but I'd put The Haunting above it.
I agree completely.
The Haunting is absolutely the most frightening film ever made, especially considering you never really see anything horrible in it. It's all left up to your imagination to scare the hell out of you.
Another great B&W scarey film is
Night of the Demon shot in England but starring Dana Andrews. It would have been even scarier if as the director wanted, the demon is never seen. But the front-office boys insisted on having the boogey-bear in a couple of scenes at the start and end of the film. Too bad, because I can imagine a better demon than they could build.
There are lots of great B&W films from the 1930s-1960s. Many of the best have been mentioned, especially
Double Indemnity,
Street Car Named Desire,
On the Waterfront,
Dr. Strangelove, and of course
Citizen Kane.
But there are some films that just need to be in B&W to get the kind of stark gritty look that they need to depict bad times and bad places. Like
Grapes of Wrath,
Dead End,
The Ox-Bow Incident,
Blackboard Jungle,
Love with the Proper Stranger,
A Face in the Crowd,
The Men (one of Brando's earliest films),
The Hill about a British stockade in North Africa in WWII where it's all sun and sand. Could say the same thing about
Beau Geste (with Gary Cooper) one of the classics as well as
They Made Me a Criminal or
I Am a Fugitive from a Chain Gang, The Roaring Twenties, and
The Maltese Falcon. War can look better in B&W as with
From Here to Eternity,
Sands of Iwo Jima,
The Story of GI Joe,
Battleground (snow and mud),
The Steel Helmet. Lots of good B&W Westerns--
High Noon,
Yellow Sky,
The Gunfighter,
Red River,
Along Came Jones, They Died With Their Boots On, The Virginian. My two favorite comedies were shot in B&W,
The Miracle of Morgan's Creek and
Hail the Conquering Hero (both of which deal with WWII issues that no other director ever touched at that time--girls dating soldiers and getting pregnant by someone she doesn't know, and young men spurned for not being in uniform because they were 4F--disqualified for health reasons). Also
Sullivan's Travels and
A Horn Blows at Midnight which Jack Benny turned into a running joke for years. Also Benny's best film, the original
To Be or Not to Be.