It's good for cured meats, the sort of sausages you don't usually see, and they do a really good value mixed salad. Or is that Lidl? They're very close to one another in Aylesbury, and close in type. It's £0.99 for a 500g bag, which is much better than Sainsbury's or Tesco - I always buy it if I'm providing salad as part of any meal I'm preparing.
Oh and fish - very good for fish for their size. Our smaller supermarkets tend to stock only breaded or battered, but both Aldi and Lidl (of a comparable size) do a range of plain fish, which suits me a lot better. More expensive on fizzy water though. But I've checked every supermarket in a 3 mile radius and I don't really think I'll improve on 12p for 2 litres!
To me they're nothing like the shops at petrol stations, but then I can't be sure that ours are anything like yours anyway