A few weeks ago i switched from Tesco to Waitrose as my main supermarket. I have not suddenly become much more wealthy but my wife is a Waitrose employee (or partner or whatever they call it) and so we both have a discount card. With the discount it works out about the same as Tesco though the quality is better and the choice is so much better.
This is despite the average Waitrose store being a fair bit smaller than the mega-Tesco store i used to do my weekly shop in. The cheese counter i especially love visiting in Waitrose, my wife works at one of these so she advises me as to which cheese to get!
I was really sold on this supermarket when i bought some bananas last week. Now i've become used to bananas being rather bland and tasteless and have continued eating them for the health benefits. When i first tried a Waitrose banana last week however i was surprised, it actually tasted of banana!