Black & White Lightroom presets: you can never have enough of them!! Each has its own pros and cons: some don’t allow anywhere near enough contrast with the resulting image looks more like someone has dragged coal over paper than a work of photographic genius, others simply desaturate all colour from the image – brilliant for some instances, but not always.
B&W Weapon from bjwok.com leaves enough details in the shadows while highlighting minor contrasts such as different shades of skin, hair definition etc. The boys from Poetikool Justice look waaay more nasty after a dose of B&W Weapon!
Once installed, you should tweak the preset to suit your own image.