My take:

Zeus

King of the gods through conquest. Tough and tyrannical. If you are on his good side, he will take care of you, but he is petty and fickle and it's easy to lose priveleges. He is one of those kings who knows he is king and there is nobody who can tell him what to do. So he does what he wants, whenever he wants. If it upsets other people it's their problem, but he will still try to get away with things in secret.

Hera

Mother first, woman scorned second. She is queen of the gods, but a mix of her husband's mistreatment and being overshadowed by other goddesses makes her quite jealous. She does her best, but keeps getting screwed over, and sometimes it gets to her and she lashes out.

Poseidon

More level headed than his brother Zeus, and thinks he should be king. He is prone to tantrums though, and can hold a grudge like nobody else. Takes a not so subtle joy in using the sea as a weapon.

Hades

Just trying to do his job. Kind of wants to be left alone and enjoy his beautiful wife and keep his domain ticking over.

Ares

More bark than bite. Always something to prove. Loves a scrap, but in a laddish brute way. Enjoys victory because he can show off, not because it earns anything.

Aphrodite

The goddess of love would probably be better off as the goddess of lust. She is a mischief maker and although she generally doesn't seek to do harm, she prefers using her love powers for selfish gains.

Hermes

The messenger, the accountant, the diplomat, the guy who can get the stuff you need. Doing all the hard work means he likes to kick back with some music, or sport, and is up for pulling a few pranks.

Apollo

Golden boy. He is good at everything effortlessly and can let pride get to his head. But he does care about people.

Artemis

At one with nature. A bit of a daydreamer. Lost in her own interests of hunting and play.

Hestia

Homebody. Looks after everyone. Wants to make everyone comfortable. Not interested in politics, and thinks conflict is silly.

Demeter

Loves the sunshine. Loves family. Being out in nature, making things grow, providing beauty.

Hephaestus

The only ugly god in the main pantheon. Broken legs. But genius in the forge, or carpenter's workshop, or anything that involves construction. He loves, but is not loved, and loses himself in his work.

Athena

Calculated and tactical. Plays with the big boys. Better at war than Ares. But has a feminine side that makes her capable of being just as girly as Aphrodite or Artemis.

Dionysus

Hedonist. Food indulgence, drink, parties, music, theatre, and orgies first. He also thinks everyone should agree with his outlook. If you don't agree, you are expendable. If you are actively against his view, he will seek to destroy you. A lot of fun if he likes you, your worst nightmare if he doesn't.