The YHA London Oxford St is a great option if location is your top priority. In the middle of wild Soho, this is Hostelling International's best shot at fun ? and they succeed. YHA Oxford St is popular with the young and decadent, and is a great jumping off point for local Soho nightlife and for the city at large. Surprisingly, it's not too loud at night, so that you can get a good rest when you come home (as long as your roommates behave themselves).
YHA Oxford St is a good value considering what rent must be like in this part of the city, but don't expect many freebies here ? they're offering the bare necessities. (But you'll save a bundle on Tube fare, because hey ? you're already here.) Rooms can be a little hot in summer and the bathrooms could use some cleaning, but it's a small sacrifice to be able to stay in the center of the world for a few nights.