Green Lantern
Green Lantern: Secret Origin, by Geoff Johns and Ivan Reis · DC, 2008
Hal Jordan is a reckless test pilot who is chosen by a dying alien to receive a power ring, the most powerful weapon in the universe, and join the Green Lantern Corps, an intergalactic police force. His mentor is a Lantern named Sinestro, who has some very firm ideas about keeping order.
Johns rebuilt Green Lantern for a new generation, and this origin story is the easiest way in. It is big, colourful space opera, with Reis's art at its most dynamic.