Of the various super-powered teams and systems in the DC Universe, the Lanterns are just about the most expansive and encompassing as you can imagine.
With it containing so many completely different factions, who are often totally at war with one another, as well as having wildly different powers and beliefs, it can sometimes be hard to track what all the various Lantern Corps are up to at any given time - especially when you combine their external dealings with the internal dramas of each separate Corps.
As much as this can be confusing, the sheer detail of each separate section of the Lantern Corps is arguably what makes the Green Lantern series so engaging. With such a deep and detailed background, the universe really feels as though it's expanding organically, with the number of individualised events reflecting that. It takes a heavy read to get up to date with all of them, sure, but it's more than worth it to feel as though you're looking at a fully articulate universe.
Between the most well known groups, such as the Green Lanterns Corps and the Sinestro Corps, to the more obscure Ultraviolet faction, every single corner of the DC universe has some form of Lantern within it - and that's pretty dang cool.
11. Green Lantern Corps
The Green Lanterns have always been - and will always be - the most important faction in the various Lantern Corps.
Not only are their powers - which rely on sheer willpower - considered one of the most powerful Lantern powers, but they are also the faction who exist as a sort of intergalactic police, and have prevented the universe from total destruction on more than one occasion.
With the DC continuum being in pretty intense turmoil almost consistency since Rebirth, the Green Lanterns have had their work somewhat cut out for them. Recent exploits involve trying to take down Zod and a planet's worth of his cult-like followers, protecting the alien race the Moliphites from their in-planet racism, and attempting to help a Parallax-possessed Superman.
If there's one thing that's consistent in regards to what is happening with the Green Lanterns, it's that it's always life-threatening, always intense, and always proves the worth of the universe's super-cops.