My daughter got a 9 in her GCSE Classical Civilisation this summer. That's the best I've ever seen.
When I was in high school, a friend of mine at the time got all Ds and Es for GCSEs (I think she totally failed a few as well). She wasn't academic. That's the worst I've ever actually seen.
(Although she was by far the only one to do badly. Many people in my year group did badly at GCSEs, just as others did well.)
For A Levels I only saw my own grades.