I lived in the UK for a long time. My experience there a was that a good roast dinner is quite nice, but difficult to find. And when you do find one, it's very expensive. This is something I found very odd. In most other countries, popular foods like this tend to be everywhere at a decent price.

And like you said, the variety of food available in the UK is great. I used to be able to find some pretty obscure ingredients for Asian/Mexican/whatever cuisine in any normal supermarket.