Law with criminology Watch
Any joint subject degree will restrict the Law or Crim modules you can do because of timetable issues. Think carefully about this - you could miss out on the areas of Law you really want to do.
Uni courses will specify the A level subjects they want (look at the course page on their website). Law is unusual and most Uni wont ask for any specific subjects - its an intellectual and highly academic subject and what they want is evidence of academic ability rather than subject skills. You could be doing 3 science subjects and with high grades still get an offer. So, if you are choosing subjects go for the subjects where you feel most confident of getting high grades. However, most people find an essay-based subject helpful once they start their degree - politics, sociology, history etc etc - and the subject matter has relevance to Law.