If I'm after a pint in a pub, I'll go for either Guinness or San Miguel.
If I'm after something stronger then single malt whiskey with water or ice. I'm feeling the Islay malts right now, smokey whiskeys have so much flavour.
I do love trying different stouts and porters where possible too. The Harp behind the English National Opera (Covent Garden) has a good variety of different ales, stouts and whatnot.
My mate once saw Benedict Cumberbatch walking down the alley behind the pub after a show at the theatre, pretty sweet I guess.
In terms of non-alcoholic drinks, I fucking love pineapple juice (which also has some other useful properties ).