Menu: Adjust -> Black & White - B/W Mixer
To create the perfect B/W image with just the right feel you can use B/W Channel Mixer. By moving the point in a color space you will set how each channel affects the result B/W image. You can really change the feel of whole image.
Here you can see an example of B&W conversion using channel mixer. The left image is converted using B/W Mixer, the right one by using Desaturate. Although both images look similar, the left one seems to have better clouds with not completely clipped highlights.
Note: The source must be a Color image.