check out www.davys.co.uk - i know it says they're wine bars, which i suppose they are really but they also do fantastic 'Davy's Old Wallop' beer, served out of metal jugs. Fantastic.
Try here.... http://www.fancyapint.com/
an excellent guide to pubs which allows you to search by tube station. It depends what type of extablishment you are looking for but heading up towards Soho it's worth checking out Waxy O'Connor's, alternatively there's a myriad of good old fashion boozers in SoHo or if you don't mind a short walk head down Piccadilly turn up one of the streets opposite the Ritz and go to Shephard Market which has a couple of great pubs and a nice atmosphere for drinking. If you're going to watch sport then this site gives a good breakdown of where to go: http://www.sportspubs.co.uk/search.php
Best pub in London is the Star Tavern in Belgrave Mews West, Knightsbridge (a 10 minute walk from Knightsbridge / Hyde Park stations). Superb beer (it's a Fullers pub) and superb food. Don't go on a Thursday night though. (It is small, and I want a seat!)
I disagree Andy, the Star is a great pub but there is a better one in the same area.. The Nags Head which I believe is on Kinnerton Mews.... great interior, atmosphere and beer plus you get the opportunity to be served by Pogo Patterson of Grange Hill fame!
Found it many a time Norman [street's called Wilton Street or mews or something for those who haven't] though I tend to think it's a bit more snobby [when you can get through the door] than the Nag's head, though both have there own quotient of stars drinking there... saw Guy Richie in the Grenadier with a bunch of lovies but the Nag's head beats it again with Tom Cruise.
I'm not going to get into a name dropping competition, lets just say the area is well endowed with stars hanging out in bars and pubs... which does remind me of having our table bumped into and drinks spilt in the Admiral Codrington many moons ago [before it's make over] turning around to find Prince Andrew offering to replace our drinks and Fergie [The Princess not the football manager!] giggling at him in the corner [ok so I did name drop... damn!]