the bull and gate
address: 389 kentish town road, kentish town, london, NW5 2TJ.
It's very easy to get here. Get a tube or train to Kentish Town, come out of the station, cross the road, and turn right for about 10 metres.
Then pay up top dollar.
The Bull & Gate have their own rather nice website at http://www.bullandgate.co.uk - useful for checking gig news and other info, and also directions if for whatever reason the above isn't good enough for you.