If you wanted to be a prosecutor in NYC, I might say St. Johns. However, since you want biglaw, I'd say Duke.
(It might be more accurate to say that Duke is the 11-13 school in the country, but it does have a top 10 reputation among lawyers and judges.)
For critics of Biglaw, it should be kept in mind that one can make enough in a couple of years there to pay off most student debt (or save a ton of cash). You work hard, but you get paid well for it. And when you want to transfer out, it's generally easier to get those small and mid-sized firm jobs with a biglaw firm on you resume. (Having a top school name there will also help in that regard. Top schools don't just get you Biglaw, they give you better shots at small and mid-sized firms as well.)