Hmmm, personally i would go for English. Law is a little ambiguous as a subject. Some unis such as Kent, seem to really like it, while others such as LSE and durham seem much less keen. I think it's considered to be an "easier" subject, although i'm sure it just depends upon where your strength lies. My sixth form doesn't offer it, but even if it did i wouldn't have done it.
At the end of the day though, pick the subject you're going to do better in, it's of no benefit to you to have 4 AAA offers, and then not make the grades.