I do most of my shopping at Tesco and Iceland simply because they are a 5 min walk from home. I go past a Lidl on the bus, so I sometimes pop in there on my way home from work.
Iceland are very good, their curries are very nice (nb Korma is not a curry) and my son loves their £1 double pepperoni pizza. I've tried numerous other, more expensive ones but he always says 'it's not as nice as the usual one'. Only a dominos pizza is better according to him. I must try the stonebaked one from Iceland - don't think we've tried that one yet.
I also regularly buy milk, bread, cheese, eggs, spread etc from there.