A lot of people would probably say that Hal Jordan is the most important Green Lantern ever. Others might say Kyle Rayner since he carried on the Corps after Hal went crazy and eradicated them. Sinestro's been said to be one of the greatest members but for us, it has to be Abin Sur.
It was this noble and dying alien of the Green Lantern Corps that brought the whole notion of of Green Lanterns to Earth. When he crashed on Earth, he used his power ring to seek out the most worthy successor and gave his ring (and smelly dirty costume) to Hal Jordan.
There is more to his story than just the tragic tale of his crash and the giving of his ring to Hal. Just as the story of Sinestro has been tweaked and updated over the years, Abin Sur's story has been fleshed out so he's not just an alien that crashed his ship on Earth.== TEASER ==
Originally, we didn't get any information on Hal Jordan's predecessor. The very first page of Showcase #22 showed his crashed ship. All it told us was he couldn't fly a spaceship very well (nevermind the fact that he could travel through space with his power ring and shouldn't have needed a ship). He crashed in the desert, knew he was dying and needed to find a replacement.
In Flashpoint: Abin Sur #1, we get to see more of Abin's past. At a young age, he understood the importance of all life. Something that he carried into his adult years when becoming a member of the Green Lantern Corps.
The real question is, why was he flying in a ship and why did he crash?
In the post-Crisis explanation, Abin went to the imprisoned Atrocitus to find out what he could tell him about the prophecy and fate of the universe (including "The Blackest Night"). Abin knew his ring would fail him when he needed it most. Transporting Atrocitus in order to find out where evil would be born, he took a ship because Earth was supposed to be the birthplace of the Black.
Whether it was the prophecy coming true or just Atrocitus egging him on, Abin showed some fear and thus, allowed Parallax to enter and weaken his will.
This allowed Atrocitus to escape (and he would be back later to cause problems for Hal Jordan and the Green Lantern Corps). Being attacked and wounded by Atrocitus, Abin and the ship were on a crash course for Earth.
The ship was headed towards Coast City. With an estimated loss of over two-thousand Earthlings, Abin did all he could to steer the ship to a remote area. This resulted in a more difficult landing which lessened the chances of his survival.
Abin Sur was one of the noblest Green Lanterns. Cherishing life, his pursuit to discover the secrets of the prophecy that would bring about The Blackest Night and cause the deaths of countless others is what brought about his death. Originally seen as just a dying purple alien that gave a power ring to Hal Jordan, we now know there were hidden layers to his character. Even recently in Green Lantern #66, we saw he has a hidden past involving Indigo from the Indigo Tribe.
Abin Sur may not have a lot of screen time in the Green Lantern movie but again, if it wasn't for him, Hal Jordan never would have had the chance to become one of the greatest Green Lanterns.