Prices change every minute, your definition of best is short but and can help on BATTERY LIFE.
Almost all batteries have a 300 cycle "life" so almost all run from an hour to a few so in this price range we can write that there is equality in life.
Be sure to try the Laptop pickers in the Buying advice forum.
Hi, I'm looking for a laptop for school this year so it would help if it were lightweight, small (less than 15"), and long battery life. The only other requirement is a core i5 processor second generation. So, what's the best I can do?