Erinyes
Also known as the Furies, they were the female spirits of Justise and vengeance. They pursue wrong doers relentlessly, until death, often driving them to suicide. They are particularly concerned with matricide. There are three Erinyes - Tisiphone, Megaera, and Alecto. The Erinyes came from the blood of Uranus when he was castrated.
Eris
Eris was the daughter of Zeus and Hera. She was the goddess of discord. In addition to her main activity of sowing discord, she frequently accompanied her brother Ares to battles. On these occasions, she rode his chariot and brought her son Strife.
Eris was unpopular and frequently snubbed as a guest by the other gods and mankind. This was not always a safe thing to do. The most dramatic example being the Trojan War, which was an indirect result of not inviting Eris to a wedding.
Eros
Eros was the son of Aphrodite. Eros was the god of love. In particular erotic, romantic and love. He is often represented blindfolded because, love is often blind. His "weapon" was darts or arrows. In either case, the tips have been magically treated to produce either uncontrollable love or insurmountable disinterested in the first person seen be Eros's victim after wounding.
In Roman times, Eros became Cupid.
Fates
The Fates have the subtle but, awesome power of deciding a man's destiny. They assigned a man to do good or evil. The most obvious choice was choosing how long a man lives. There were three Fates. Clotho, the spinner, who spun the thread of life. Lachesis, the measurer, who chose the lot in life one will have and measured off how long it is to be. Atropos, she who can not be turned, who, at death with her shears, cuts the thread of life.
The Fates were old and predated the gods. It was not entirely clear how far their power extends. It was possible that they determine the fate of the gods as well. In any case, not even the most powerful was willing to trifle with them.
Graces
They were the daughters of Zeus and Eurynome. There are three Graces: Aglaia (Splendor), Euphrosyne (Mirth), and Thalia (Good Cheer). They were known for singing and dancing for the gods.
Hebe
Hebe was the daughter of Zeus and Hera. She was the goddess of youth. She, along with Ganymede were the cupbearers to the gods. Hebe was Hercules' wife.
Helius
Helius was the Greek sun god. He may be thought of as a personification of the sun. He became rather overshadowed by Apollo the lord of the sun. He was the son of Hyperion, who was also a sun god.
His role was to drive his chariot across the sky to provide daylight. He was accompanied in this daily trip by his sister Eos who heralded his arrival. He returned home at night on the river Oceanus in an enormous golden cup to hide the light. During his daily trip, he sees much of what is happening on the earth. Due to his availability as a witness, many Greeks swore their oaths in his name. It was on one of his daily trips that he spotted the abduction of Persephone.
Helius was away on his daily rounds when the gods divided up the world. Having otherwise completed this complex task, Zeus was reluctant to reopen the issue. This was resolved when Helius spotted the unassigned island of Rhodes and asked for it. The other gods were happy to give it to him. Helius remained the patron god of Rhodes throughout the classic period. Helius is the figure represented in the famous Colossus of Rhodes statue, that was considered one of the seven wonders of the ancient world.
Helius married Perse and had a number of children, most of whom had rather unsavory reputations. While Helius did not seem to have these bad traits, he remained loyal to all of his children. A number of the children accompanied him from time to time on his chariot.
Helius also had quite a number of mistresses and affairs which produced children as well. The best known being Phaethon.
The most tragically poetic of these affairs began when during his daily tour he noticed Aphrodite and Ares carrying on. As was his habit in these matters he reported it to her husband Hephaestus. To retaliate, Aphrodite used her abilities to cause Helius to fall in love with Leucothoe, a Persian princess. Helius assumed the form of the girl's mother to gain access to her bedroom. Once inside, he assumed his normal form and seduced her. Word of this got to one on Helius' mistresses, the nymph Clytie. Clytie informed the girl's father who then buried Loucothoe alive, killing her. In his grief, Helius changed her body into the first frankincense. This put Clytie on the outs with Helius. She then wasted away. On her death, she became the first heliotrope, a flower whose blossom follows the sun across the sky.
Horae
The Horae, also known as the Hours or the Seasons are daughters of Zeus and Themis. Most accounts identify three - Thallo (Spring), Auxo (Summer), Carpo (Harvest, Autumn, Fall). In Athens, Auxo was often omitted. They became associated with ethical properties, possibly from their connection with the order and regularity of nature - the change of seasons. Hesiod names them - Eunomia (law and order), Dike (justice), and Eirene (peace). They also served as the wardens of the sky, rolling the clouds back from the gates of Mt. Olympus, for the gods to go off in their chariots.
Iris
Iris was the daughter of Thaumas and Oceanus in Electra. She was goddess of the rainbow. She served the gods, especially Hera, as a messanger.
Leto
Leto was the daughter of Coeus and Phoebe. She had two children with Zeus, Apollo and Artemis. Her children maintained a close family loyalty. This was shown when Apollo killed the Python which persued his mother and when Apollo and Artemis punished Niobe when she boasted that her was a better mother than Leto.
Maia
Maia was a daughter of Atlas. She was one of Zeus' lovers. She, along with Zeus was the mother of Hermes.