One of the interesting things about the UK, demonstrated I suspect by this comment, is how incredibly tied to social status / class they are. Your supermarket is arguably more important than say, your car, or your watch, or whatever else. I remember people being bullied at school because their parents shopped (or it was claimed they shopped) at certain stores. Really quite bizarre looking back.
That said, arnonejoe isn't wrong... (well a little. M&S and Booths are good too.)