which of the boys has the best qualities for a potential leader and why?

Ralph is elected chief by the boys. He had a kind face, "that proclaimed no devil." He also had the conch, which was like a megaphone from the adult world. Although the only real intelligence can be traced to Piggy, he is fat and subject to ridicule. Certainly Piggy has a lot of knowledge. He knows things about science that the other boys simply don't know. He knows what to do with the conch, what a signal fire should look like, the relative time of day according to the sun....Piggy also thinks methodically. At one point Ralph wishes he could think "step by step" like Piggy does. Piggy exists on civilization. In a Darwinian Chaotic place like the island, guys like Piggy do not survive. For all Piggy's brains, he is "no leader". From years of torment he has turned into the classic school-yard victim. He doesn't like physical work and really helps himself become an outcast. Jack is also a logical leader because of his assertiveness and charisma.