Historical version 4 of Category Sushi (view current version)
There are two rough categories of places to get sushi from in London — Japanese restaurants/cafes/takeaways such as Zipangu, WC2H 7JJ, and generic lunchtime food (sandwich/salad/soup/sushi) shops, such as Eat, WC1V 6AA. The former obviously is generally better quality; the latter is often more convenient and cheaper.