I'm not the tiniest bit snobby about shopping and like a bargain, but I can't stand Aldi. I have bought the odd jar of instant coffee [which is nice] when I have been in there with my daughter, who really likes the shop. I like a little wander about Lidl, nice wide aisles and always stock up on their W5 washing up liquid and clear kitchen bin bags. They also do some kids' lunchbox size peppers, tomatoes and the like.
A lot of it depends on how much you like preparing food and the cooking experience. I like everything easy with zero chance of it not turning out well. Meat, plain frozen fish and tinned fish, sauces [tomato, bown, horseradish, mayonnaise etc], grapes, ready to eat spinach, asparagus soup, and other jars and cans all come from M & S. I find they are best.
It's Morrisons for yoghurts as they do the widest range of Longley Farm live yoghurts, also the best bananas. Asda is very handy for all the rest as they have a rapid turnover of bread - I mainly eat Milk Roll, Danish, or crustless bread [light and no substance but it's what I like]. The middle aisles in Lidl have some good bargains for everything you didn't know you really needed and I have to make myself be picky about what I buy. Aldi middle aisles don't tempt me.
Fortunately for me all these shops and many, many more are almost on top of each other, but I haven't found decent plums in any of them this year. I live near a One Stop for filtered milk and a Heron shop by the bus stop where I can pick up the cheap stuff such as tinned mushy peas, Holland's potato and meat pies etc.
Iceland do big business around here and they do have quite a lot of interesting things, although they change them for something else very quickly. In the local magistrates court lists, most of shoplifters are in court for stealing from Iceland. So they must have a fair share of scummy customers.
I never, ever buy from the ubiquitous continental markets that pop up all the time - I don't fancy any of it, so I do turn up my nose at them.