I've never been a fan of classic films, so I haven't seen many black and white movies. I did really enjoy Schindler's List, though. I thought the lack of colour really helped the film hit home with it's audience.
I LOVE black and white films. The techniques used in colour saturation i.e. costumes, make-up, filters etc ... is quite different to enable the shade and tones of blacks and greys help with propelling the story emotionally. The same colour guide wouldn't be used for ordinary colour film. Technique aside, I'm a sucker for The Elephant Man. If the film had been released in colour it wouldn't have had the same emotional momentum and impact. Go B&W. I also love B&W photography.