Asda? Cheap, but kinda meh
Tesco? Pretty good, but more expensive
Morrisons? Good and cheap, especially with fresh stuff
Sainsburys? Good, but expensive
Waitrose? Good and very expensive
M&S? Very good and expensive Aldi? Don't wanna risk my health
Lidl? Same as above
I definitely prefer Morrisons. Their fresh range is really good and really cheap compared to the rest of the Big 4. At Morrisons you can buy 3 bags of fruits for £2. At Tesco you get 1 for £1.75 or 2 for £2.50 if you are lucky. Their meat section is also the best among the Big 4 and almost market-like.
Tesco has become too expensive tbh. Asda was always cheap, but a lot of their cheap stuff is pretty bad. Sainsburys I really like and the have the best bakery section, but they are the most expensive among the Big 4.
M&S I absolutely love, but it's even more expensive than Sainsburys.
Waitrose is expensive, but not much better than your regular supermarket.
Co-operative is pretty bad and pretty expensive too.
Haven't shopped in Aldi & Lidl for more than 5 years, but when I did the quality was the lowest of the low.