My understanding is that 99% of firms will care about what GPA you got over what classes you took to get it. They know you'll come out of law school knowing the basics, and expect you'll have to be taught the rest.
Take Torts for example. You learn the basics of tort law in law school. You discover the elements of negligence, learn about causation, and get some idea of comparative and contributive negligence. That is all nice background information. When you get to New York and you get assigned to an employment case of wrongful discharge, your tort class will probably not have really prepared you for it. Even if you get a negligence case, you still need to research New York's variety of negligence. You'll have to find a New York case listing the elements; you can't just write them down from memory or quote that California case from your textbook. You then have to find out what type of comparative or contributive negligence system New York uses. Oh, and start all over again next month when they hand you a tort case in New Jersey.
I expect classes to be like having read and studied a really good secondary source. They'll make you knowledgeable in an area, but you still have all the real work ahead of you.
So game the system for a higher grade if you have to. A law firm might get suspicious if you take all Pass/Fail classes your last year of law school, though.