If cocktails are the main event then it makes sense to pay a bit extra for something decent? A good cocktail in East Dulwich is now easily ?8 to ?10 so you'll pay more up west with the classic hotel bars (Savoy, Ritz etc) easily doing ?15 mark upwards. But you'll get some snacks and white gloved service for that and on the plus side you'll only want two at the strength they mix them. If it's in the ?10 to ?15 mid range price per drink my picks for Central would be: - The Langham Hotel just north of Oxford Circus - Skylon in the Royal Festival Hall which has lounge tables close to the bar just for drinkers. And a view of the river. - Brasserie Zedel has the bar Americain and is also fun https://www.brasseriezedel.com darn it..it will be ages before I get back to any of these places again....have fun...