4. Ganthet
After Hal Jordan decimated the Corps, Ganthet was the last living member of the Guardians and with one last ring to give, he chose wisely with Kyle Rayner to keep the light burning. Along with Sayd, Ganthet was the one who had the best interests of the universe at heart amongst his peers while never giving up on his own emotional center. Eventually the other Guardians kicked him from their circle but Ganthet's heart never dimmed and during the "Blackest Night" he inducted himself into the very police force he helped create. He also brought to life the Blue Lantern Corps (emotion: hope) and though he carried a different insignia, the loyalty and love for his Lanterns remained as the Blue Lanterns essentially existed to provide back-up for the Green Lanterns rather than simply be an equal force of their own. His embracing of emotion led to his downfall and his fellow Oans brainwashed him and wiped away all who he was and stood for. As the Guardians began their maniacal and short-sighted new goal of wiping away all emotion in the universe, Ganthet was in the center, breaking the hearts of all those who had grown to love him.