Zeus- I think that should be you. Plenty of possible leaders for that one because Zeus is such a multi-facet god. Make sure you do one thing if you want to roleplay this : play the unfaithful husband : ally yourself to Hera and betray her for any of the other females. (Yes Zeus only did it with the Mortal Girls but hey, Gods gotta be good too right ?)
Hera- I'd go with Isabel, she'll be perfect for the . .. .. .. .. .y side of Hera which often has the best of her when she's dealing with the other gods. Plus the expansive side does give away the motherly aspect of her. Victoria could also be a possibility but I'd keep the english to make Elizabeth as Athena.
Ares- Ok, you have a lot of choices here. Most agressive leaders could fit it : the Khans, Shaka, Ragnar, Toku (who really is the all war guy),... Really a lot of choices here. I'd avoir Monty though, he'd be to crazy. But that may be because I don't like monty
Julius Ceasar of course does give off that Mars/Ares feeling. (Plus Prets !)
Hermes- Hannibal is my favourite. Runner ups are : Mansa, Huayna, Pacal and Darius.
Poseidon- Ragnar is top choice, obviously. Fits perfectly with the water theme and the angry side of Poseidon.
Hades- This one is tough, I think I'd go with Saladin (keeper of Tartarus), at least some spiritual leader. You might go with Monty for some crazy death bringer, but that's not really what Hades does (Monty does have that death feel to him though) and I already said I didn't like Monty.
Hephaestus- Some industrious leader : you want him to be a builder. Augustus Ceaser with his metal-age unit comes to mind (he might be too good-looking though, plus if you take Julius as Ares this is ruled out). Roosevelt and his organized trait might be nice too. Not De Gaulle though : Hephaestus is definitively not charismatic !
Demeter- ok, this one's a bit tricky 'cause she's a goddess, and I don't find that any of the female leaders have the peacefull feeling you get off of Demeter or any "feeding mother" feel either. So if I were to put her in, I'd cheat by putting her as a man. Then I'd either go with one of the indians (your choice) for the peace-hippie feeling (and fast worker to work the mother earth) or with Mehmed for expansive and Hamams.
Athena- Elizabeth. Just feels like the perfect Athena to me. Any questions ?
Apollo- Ok, this one HAS to be Suryavarman II. He's just such a sunny guy !
More seriously, he's perfect : both expansive and creative, the sun/healer and the artistic sides of Apollo.
Artemis- Boudica or if you don't mind cross-dressing, Sitting "Archery Man" Bull.
Aphrodite- Catherine for that . .. .. .. .. .y lovin' we've all learned to like ! Could anyone just fit the role better ?
Damn, now you've got me wanting to play such a game. I think I just might give it a try.