The Devonshire Arms sits on Kentish Town Road in Camden Town, a mock-Tudor pub known to everyone as The Dev. By Wikipedia's account it is the longest-surviving goth pub in London and a focus for the city's alternative scene.
It is a music pub first. The dark interior runs goth, punk, metal, indie, and rock, with live bands and DJs through the week. Come for a pint among the black-clad regulars and a loud night. Skip it if heavy music is not your thing, because the stereo sets the whole mood here.