Either Easton or Louisville Slugger. The lightest is not always the best, it depends on the child's strength, and how fast his bat speed is. Heavier bats give more power, but can slow down a swing dramatically. lighter bats, while giving less power, give a higher chance for contact. Pick what type of hitter is using the bat.

I am always a fan of Easton. The best bat weight wise is the bat that can be handled and swung properly by the individual. Have the person who is getting the bat try out a couple of different swings. Look for the proper mechanics during the practice swings. Sometimes having a light bat can cause too quick of swings and "over" swings causing alot more swings and misses and pop ups. A properly weighted bat can really influence a person's success at the plate.