Folks often assume that there is some magical undergrad major that will open up every law school admissions door to which they’d like access. These people are sorely mistaken. There is no “best” major for getting into law school. Every curriculum for every major is different at every undergraduate institution, giving admissions officers no baseline by which to judge the quality of your major.
What law school admissions officers are looking for is analytical aptitude. Nearly every undergraduate major (and indeed, college in general) involves using and honing one’s analytical ability to some degree. Being an English major does not mean you’ll have a leg up on writing legal briefs. If anything, the florid prose you’ll use in English classes will work to your detriment in law school. Studying whatever pre-law courses your school offers might be fun, and could possibly get you running down hill when it comes to studying in law school, but they won’t make you any more likely to get accepted.
The only real exceptions to the above are technical degrees. Studying subjects like physics, computer science and engineering could be a boon to your future legal career (and possibly also your law school admissions prospects) as most firms want their patent lawyers to have proficiency in their area of practice.
Otherwise, my advice to you is to do as well as you possibly can in whatever field you study. Law school admissions officers don’t care so much what you study as whether you work hard and have analytical ability (which you can highlight in your personal statement). So don’t fret if you’ve been toiling away in the Art History salt mines and have suddenly realized a legal career is the future you want.
Just get the best grades and LSAT score you can, and write a kick-ass personal statement, and you’ll be no worse off than some English major who thinks he’s getting one over on you.