It depends a huge amount on what university you want to attend. To become a lawyer (Barrister or Solicitor) you will need to gain an Accredited LLB(Hons) degree and these courses are usually very over-subscribed.
For example, the top Law Schools in England are at Oxbridge and Bristol. This is not solely because of the standard of teaching - it's about supply and demand. These universities are very popular. You'll be looking at three or even four A levels with at least one Grade A before they'll even look at you.
Other good Law Schools are at the University of the West of England and Southampton Solent. They will probably be happy to accept three B's.
For subjects they would like English Language but most will be fairly catholic and accept other traditional academic subjects providing your grades are ok. Ironically, Law A level is not given a higher 'value' than any other.
Don't even think about including subjects such as 'Media Studies' or anything like that in your collection. They want traditional 'serious' subjects. See the university web sites for more info.
