I live in Madison right now, and I fear that I'm being spoiled on good beer. Between New Glarus, Capitol Brewery, Ale Asylum, and Lake Louie the selection is amazing. I went down to Orlando for a conference not too long ago, and found that the only thing drinkable to me was Guiness.

When I went to London a couple of years back, I found that the beer was actually quite enjoyable, though I can't remember which beers I had while I was there. (More as a result of time rather than of the beer)