If it's a weekday, one in Holborn, Central london. On a Saturday, or any day I was home, I would use the one on Ewhurst Road, SE4 - it's about a mile and a bit from HOP train station and the chap is really nice - I think he's only open Wednesdays to Saturdays though.

Hugh Fearnley Whittingstall assures me that alcohol actually has the oppsite effect - it draws moisture out of the meat and makes it dry, especially if marinated in it..I think beef can take being cooked in it though...but you're right, it's not really a cheap option necessarily!