Hal Jordon (the most famous Earth Green Lantern)
Unlike his successors, Alan was not a member of the Green Lantern Corp! Alan Scott (an engineer) discovered a mystic flame that fell to Earth thousands of years ago. The flame told him how to a mystic "power ring". After doing so, Alan used the ring (which gave it's user roughly the same powers as a real Power Ring) to fight crime. However, he had two weaknesses: the ring needed be "charge" every 24 hours and it couldn't affect wood. He founded the Justice Society of America. Due the fact Alan made his ring, the Guardians of the Universe (the head of the Green Lantern Corp.) let him keep it.
The most famous the Green Lanterns, he also destroyed the corp. Hal was a pilot chosen by Abin Sur's (another Green Lantern) corp. Power Ring as his successor. He was a great Lantern... until his home city was destroyed. This drove him insane to the point he merged with Parallax (a fear entity) and destroyed the Corp.
Guy was chosen to succeed Hal (before he destroyed the corp.). But, he was put in a coma, when his power battery blew up. He later came out of the coma emotionally unstable, but did help in the Crisis of Infinite Earths and Blackest Night.
Before Hal destroyed the Corp., John became the first African American Lantern. Hal temporally
left the Corp, so John filled in for him. He was put in and out of action alot. He became the first mortal Guardian of the Universe and joined the Darkstars after the Corp. was destroyed.
Kyle was a struggling freelance artist that Ganthet (the last Guardian) gave a power ring. He helped rebuilt the corp. (although it was less impressive than the last). He fought in the Sinestro Corp. War and died in Blackest Night, to save the Guardian's planet, Oa.