Welcome to Gaia! ::

Reasons: Sentry is like, invincible.

And Green Lantern is the freaking Green Lantern.

Constructs of green 'solid-energy,' which can vary from microscopic to tremendous in size and/or complexity and are limited by the imagination.

Flight, including flight at speeds beyond that of light, although this does create an enormous expenditure of energy; users tend to rely on using wormholes for long distance travel.

Relatively instantaneous transport across the galaxy and to other galaxies through generated wormholes

Destructive plasma bolts

Energy force beams that can be used to capture, hold and manipulate solid objects

The rings can act as semi-sentient computers and accesses information through its connection with the Book of Oa. The rings have problem-solving skills but they cannot make decisions or take actions on their own, and must be given directives by the wearer.

Time travel (One solitary power ring cannot generate enough power for time travel; several power rings are needed to complete this feat.)

Telepathy

Translation of nearly all languages

Force field generation, a protective aura used to shield the wearer from the rigors of the vacuum of space. Strength and durability of force field in combat is limited by the user's will power. Contrary to some canon, a Green Lantern ring does not automatically protect its wearer from harm but must be willed into existence.

Creation and emission of certain types of Radiation, including simulated kryptonite radiation.

Generation of mental "earplugs" to block out telepathic communication and manipulation.

Render user invisible.

Allow wearer to phase through solid objects

Put humans into a state of suspended animation

Accelerated healing of wounds, protection and treatment from viruses and biological attacks and certain surgical procedures including reattachment of severed limbs and digits. More advanced medical procedures must be performed manually and are limited by the wearer's knowledge of medicine.

Size manipulation allowing ring bearers to grow or shrink in size, the extent of which has not been explored.

In Green Lantern: First Flight Sinestro was able to "reconnect synapses" in the brain of a dead criminal in order to extract information via a kind of guided discussion.

Teleportation (an ability that has not been used in quite some time and may be outside the ability of modern Green Lanterns)

Virtual shape-shifting by generating a hard-lined holographic disguise around the ring bearer.

Can "digitize" the wearer and absorb them into the ring where they can live in a wearer-generated "world" of their own nearly indefinitely.

Diagnostic capabilities