There's actually some great restaurants in London. . as for the typical english food, though, it's too bland for me. I ate at a Bangladeshi place that was awesome, quite a few Indian restaurants, etc. Still, London may be my favorite city I've been to.
The best food all around for a city, IMO, is New Orleans. Nowhere else is even close. 2nd it would be a toss up between Chicago and New York, although oddly enough you can throw a rock in any direction in Scottsdale and hit a good restaurant.