It got me to thinking about the pantheon of the DCU. It doesn't begin and end with God, but rather branches out in a number of directions, as different stories and characters, over the years, have helped to coalesce the DCU pantheon. Here's the map of the DCU Pantheon as far as I've seen it, starting with God and working my way down.
Vague and Undefined, the concept of God in the DCU is rarely seen, but is always assumed to be at the very top of this list. He is also sometimes known as as "The Presence".
The Source is the other-worldly authority for the New Gods on New Genesis. It's un-seen, except for when it writes a message in flames upon a wall - usually delivering a message of grave importance, but usually wrapped in a riddle. The Source has been described as an aspect of God, or an other-worldly being altogether.
This character, I think, is one of God' Angels, brought down to the mortal plane to join the Justice League. (It was during Grant Morrison's run on the series) I suppose, on the grand scale of things, he's not a big member of the DCU Heaven - he just works there.
The Spectre is God's go-to guy to take care of some of the more nasty corners of the DCU. It does beg the question, would God really approve of all the grizzly deaths the Spectre commits in his name? Probably not - but the Spectre also serves as a balance to a greater foe...
The Spectre's opposite number, having the same post the Spectre now has. He causes all sorts of messes for Earth. Just like the Spectre,Eclipso needs a human host.
The Kindly Ones
These three ladies, also known as the Furies and the Fates, are said to be above the Gods - even being able to kill them if they commit a crime of murder against a family member. The Kindly Ones killed Morpheus for the death of Morpheus son, who he had killed so he could be at peace.
The Lords of Chaos and Order
The two sides of Chaos and Order usually effect the magical side of the DCU, with agents like Doctor Fate, Hawk, and Dove acting to balance the scales when Chaos gets out of hand.
Seven separate beings who are the personification of their respective concepts. Destiny, Dream, Death, Destruction, Desire, Despair, and Delirium/Delight. The Endless are said to be more than Gods - being the actual concepts they are named after. From the creation of the Universe, down to it's final end, the Endless represent their respective domains and influence and serve the people who enter their realms.
The Endless seem less like over-seeing gods, and are more like facts - they exist, and they control and maintain their respective domains. They can die, as Death and Despair once did - but they replaced with a new, yet similar, being. Also - it is not necessary for the Endless to be proactive in their roles. Destruction famously left his job when the Atomic Age began, deciding it was best to let destruction happen on it's own, instead of orchestrating it. BUT - there is a cost to one of the Endless leaving their job. When Dream was captured by a wizard for nearly a century, it effected many people in respects to their dreams. (Thus effecting characters like Wesley Dodds, who became the 1940s Sandman)
The Endless cover a lot of the human condition, but not all of it. I think that's where the Emotional Spectrum comes in. It's not like the Endless, where they are personified concepts or emotions, but rather a more tangible power. We're so far seen a few of the sources of the Emotional Spectrum, like Ion, who represents Will Power for the Green Lantern Corps, and Parallax, who represents fear for the Sinestro Corps. These creatures are not necessarily as powerful as the Endless - but they definitely fill any gaps the Endless left out, and vice-versa. (There's no color of Depression, for example - but that Emotion is cover by "Despair of the Endless".)
The New Gods
While seemingly just as mortal as other Super-Humans, the New Gods certainly serve a purpose in the DCU Celestial Hierarchy. Being representatives of the 4th World (The Universe apparently having gone through 3 previous iterations.) Evil is equally represented with Darkseid on his planet of Apocalypse. Something about the New Gods is important to the DCU - as evidenced by one occassion of the Spectre deciding to destroy Darkseid - but having Darkseid instantly reform - being untouchable by the Spectre. Something in the Universe demands the presence of New Gods - but it is never explicitly explained. Also - the New Gods eventually do die out, having their souls returned to the Source. How this plays in the grand scheme of things is unexplained.
Like the Greek Gods who appear in Wonder Woman, these are probably the lowest gods on the totem pole, as they can interact with mortals, and can even be killed. They are dependent on faith from those who believe - and as such are less powerful in the modern day, forcing them to find other roles to fuel their powers. (Athena, for example, gains more power from the concept of Knowledge, since few actually believe in her a god anymore)
The human-inspired pantheon covers a wide range of mythological characters - and not just human ones. For example, Flamebird (in Action Comics) has manifested it's self through Thara Ak-Var.
The Phantom Stranger
There are a number of magically endowed figures in the DCU who act as guides. While not gods, they are more likely servants, playing the roles they have. They do play an important part in the DCU as a whole - managing and protecting the balance of Magic and protecting the Earth and Universe. A being like Shazam, for example, might do his part through the Champions he chooses - like Captain Marvel.
The Devil and Hell
Probably on the same level as the Greek gods in Wonder Woman comics, there is also the opposite of the gods and Heaven - demons and hell. The way demons interact with the DCU world, almost on a daily basis, seems to prescribe that what they lack in power, they make up for in numbers - giving the heroes of the DCU plenty to fight against and battle. Characters like John Constantine probably deal more with this side of the DCU far more than a character like Superman.
There is also a complex hierarchy of hell, with the original devil, dubbed "Lucifer Morningstar" having abdicating his throne. Other demons of similar power-level serve to fill that void, like "The First of the Fallen" - the defacto representation of the devil for characters like John Constantine. (The pantheon of hell developed this way because of various different writers, often-times wanting to use the same character - "The Devil" -, instead use creations similar to the original concept. Basically, it's writers trying not to step on each other's toes.)
That's the DCU Pantheon as far as I can see it. The mix of Vertigo-Titles, regular DC Comic books - all of it develops this incredible and rich concept of both heaven and hell - and everything in between. It's all predicated on the need for the heroes and villains to interact with either celestial or demonic characters - but it still forms a interesting story when weaved together.