The Greeks have given humans some of the greatest fantasy stories of all time.  Everything from the works of Homer to the legends of the Greek gods have inspired gamers to play characters of legend and greatness.  The Greek pantheon of powers are strong and youthful, and bring with them a feeling of power and majesty not found with many others.  Therefore, the Greeks hold sway over much of the planes.  May they inspire greatness in your game.  As for resources, I used (in order of age): (1) Legends & Lore by James M. Ward and Troy Denning [pgs. 102 - 119], (2) On Hallowed Ground by Colin McComb [pgs. 114 - 129], and (3) Dragon Magazine, "Do-It-Yourself Dieties" by Stephen Kenson [pg. 34].   All these works help me create this pantheon guide for those interested in playing Greeks.  All the gods below are in the following form:
 

Diety	Power Level	Diety Alignment	Worshipper Alignment
Portfolio	Symbol	Typical Worshippers
Domains		Favored Weapon(s)

In all of the forms, one domain will be in bold.  To keep the flavor of the diety, it is highly recommended that clerics of that diety chooses that as one of his domains.

Zeus	Greater	Neutral	Any
God of the Heavens, Leaders, and Thunder	Fist holding lightning	Fighters, Nobels, Rulers
Air, Destruction, Protection, Strength		Halfspear & Javalin

Aphrodite	Intermediate	Chaotic Good	Any
Goddess of Love and Beauty	Seashell	Lovers, Bards, Rogues
Chaos, Luck, Protection, Trickery		Stilleto (Dagger)

Apollo	Intermediate	Chaotic Good	Any Good
God of Light, Music, Prophesy, Medicine	Lyre	Bards, Rangers, Seers, Shepards, Elves
Good, Healing, Knowledge, Sun		Whip

Ares	Intermediate	Chaotic Evil	Any Evil or CN
God of War, Strike, and Killing	Spear	Soldiers, Assassins, Orcs
Destruction, Evil, Strength, War		Short or Long Spear

Artemis	Intermediate	Neutral Good	Any non-Evil
Goddess of Hunting, Wild Beasts, Waxing Moon	Bow and Arrow over the Moon	Women, Rangers, Hunters
Animal, Good, Protection, Trickery		Short or Long Bow

Athena	Intermediate	Lawful Good	Any Good
Godess of Tactical War, Wisdom, and Crafts	Owl	Paladins, Generals, Scholars, Gnomes
Good, Knowledge, Law, War		Long Sword

Demeter	Intermediate	Neutral Good	Any non-Evil
Goddess of Agriculture	Mare's Head	Farmers, Druids, Rangers, Halflings
Animal, Earth, Plant, Protection		Scyth

Dionysus	Intermediate	Chaotic Neutral	Any non-Lawful
God of Wine, Insanity	Staff with Pine Cone tip in Vines	Barbarians, Partiers, Bards
Chaos, Luck, Plant, Trickery		Quarterstaff

Hades	Greater	Lawful Neutral (Evil)	Any
God of Death, Wealth	Black Ram	Necromancers, Merchants
Death, Destruction, Law, Magic		Exacuter's Axe (Battle Axe)

Hecate	Intermediate	Chaotic Evil	Any
Goddess of Magic and the Waning Moon	Setting Moon	Wizards, Sorcerers, Cults
Evil, Knowledge, Magic, Trickery		Darts

Hephaestus	Intermediate	Neutral Good	Any
God of Smithing, Craft	Hammer and Anvil	Blacksmiths, Artisans, Dwarves
Earth, Fire, Protection, Strength		War Hammer

Hera	Greater	Neutral	Any
Goddess of Marriage and Intrigue	Fan of Peacock Feathers	Mothers, Wives, Women of Power
Healing, Luck, Magic, Protection		Light Mace

Hermes	Intermediate	Chaotic Good	Any non-Lawful
God of Travel, Trade, Gambling, and Thieves	Caduceus	Rogues, Travelers, Messangers, Merchants
Chaos, Luck, Travel, Trickery		Rapier

Nike	Lesser	Lawful Neutral	Any
Goddess of Victory	Winged Women	Warriors, Barbarians
Air, Luck, Strength, Travel		Short Sword

Poseidon	Greater	Chaotic Neutral	Any
God of Waterways, Seas, and Earthquakes	Trident	Sailors, Horsemen
Chaos, Death, Travel, Water		Trident