For my Sunless Citadel campaign, I wanted to depart from the Forgotten Realms where I've been running for the last 4 years. I have no problem with the Realms and actually like much of it's flavor, but I've run a full campaign to Level 20 there and I'm currently running the "apprentices" to a different group of Level 20 characters that is based there.
I thought about Greyhawk, which I love, and if memory serves DnD 3.X used it as it's default, which the Sunless Citadel was designed for. But, I'm a bit rusty on Oerth and didn't want to get sidetracked with research.
So I settled on using elements of DnD 4E's Nentir Vale. I always liked the bits of it that I read about under 4E, even the Points of Light narrative. I'm not sure exactly how tied I am to the Vale, but I definitely decided to use it's Deities.
Tribality was kind enough to work out each the Vale God's Domains, which I'm reposting here (thank you, Shawn Ellsworth for doing the heavy lifting). One of the characters in my campaign, Lothar, is a Cleric of the Raven Queen. Additionally, a cleric of Pelor maintains a Shrine and a Holy Site and a cleric of Erathis is an advisor to the Mayor.
Good and Neutral Deities
Avandra (CG)
Goddess of change, luck, trade, travel
Domain Trickery
Symbol Three stacked wavy lines
Bahamut (LG)
Dragon god of justice, protection, nobility, and honor
Domain Life, War
Symbol Dragon’s head in profile
Corellon (CG)
God of arcane magic, spring, beauty and the arts revered primarily by elves
Domain Light
Symbol Starburst
Erathis (LN)
Goddess of civilization and invention
Domain Knowledge
Symbol Upper half of a clockwork gear
Ioun (N)
Goddess of knowledge, skill, and prophecy revered primarily by scholars, magic-users
Domain Knowledge
Symbol Crook shaped like a stylized eye
Kord (CN)
God of the storm, strength and battle revered by warriors
Domain Tempest
Symbol Sword with a lightning bolt cross guard
Melora (N)
Goddess of the wilderness and the sea
Domain Nature, Tempest
Symbol Seashell with a wavelike swirl
Moradin (LG)
God of creation, artisans, family, revered primarily by dwarves
Domain Knowledge, War
Symbol Anvil
Pelor (NG)
God of the sun, summer, agriculture and time
Domain Life, Light
Symbol Circle with six outwardly radiating points
Sehanine (CG)
Goddess of trickery, love, moon and autumn revered by elves
Domain Trickery
Symbol Crescent moon
The Raven Queen (LN)
Goddess of death, fate, winter
Domain Death, Life
Symbol Raven’s head in profile
Evil Deities
Asmodeus (LE)
King of the Nine Hells and god of power, domination and tyranny
Domain Trickery
Symbol Three triangles in tight formation
Bane (LE)
God of war and conquest
Domain War
Symbol Claw with three talons pointing down
Gruumsh (CE)
God of destruction revered by orcs
Domain Tempest, War
Symbol Unblinking triangular eye with bony protrusions
Lolth (CE)
Goddess of shadows, lies, and spiders revered by the drow
Domain Trickery
Symbol Eight-pointed star with a web motif; spider
Tharizdun (CE)
Creator of the Abyss and god of annihilation and madness
Domain Trickery
Symbol Spiral
Ashardalon (LE)*
Dragon god of wealth, greed, and vengeance
Domain Trickery, War
Symbol Two red, fiery eyes
Torog (NE)
God of the Underdark and imprisonment
Domain Death
Symbol "T" attached to a circular shackle
Vecna (NE)
God of undead, necromancy, and secrets
Domain Death, Knowledge
Symbol Partially shattered one-eyed skull
Xardoz (LE)
God of vampires
Domain Death, Grave
Symbol Wolf with bat wings
Zehir (CE)
God of darkness, poison, and assassins
Domain Death, Trickery
Symbol Snake in the shape of a dagger
* In a previous campaign a conspiracy of Chromatic Dragons, tired of Tiamat's failures, murdered her in the Abyss as part of a ritual to resurrect her brother, Vorel -- the Tarrasque. After Vorel's destruction, Ashardalon boldly grabbed her domain and portfolio.