Bonus London edition!
So I went to visit a friend in London. I know a week is hardly enough time to make a decision about a place, but here are my initial thoughts: I found a bunch of "craft beer" pubs here, but they were all super trendy, and crazy expensive. Like 6-10 pounds per pint, and quality was pretty middling, compared to "craft" beers in the US. But, maybe of the dozen or so I tried, I just got all the bland ones.
Also, a lot of the pubs are owned by chains now. Nicholson's pubs are decent, as far as selection and price (more like 4-5 pounds per pint), but my favorite were the Samuel Smith pubs. Many of them have the Old Brewery Bitter on cask/hand pump, and they all seem to have the Extra Stout on nitro. Their Dark Mild was good too. The pubs seem to be the stereotypical "British pub" of my imagination: 19th century styling, dark wood, and at Ye Olde Cheshire Cheese the front door is on a narrow alley, and you can sit in the basement alcoves.
I have been pretty impressed by the ciders here. I had a handful of them at one of the craft places, and they were really good, although most tend to be pretty sweet.