The number one player uses Thor. And XpT_Cyclone is the highest rated Oranos, and extremely good as such.
But Isis is of course up there with Thor and Oranos. I think the easiest way to look at it is consider what god is the all around best for every civilization. Most people agree that the best of each civ is Thor for norse, Isis for egypt (although RA is not excactly bad), Oranos for atlantean and Zeus for greeks.
Thor: Has cheaper and better dwarves, cheaper armory ups (and gets them anytime) and no particular weaknesses. The only god who can do Ragnarok and Flaming Weapons combo (which is OP)
Isis: Strong, fast heroic with Ancestors/Eclipse combo (also OP). Protecting monuments and the best elephants in the game (when fully upgraded).
The ingame info can probably tell you this just as easy as me, but since you asked for it I will continue ;P
Oranos: Gets faster human soldiers, has good god paths. His superfast turma are probably the best raiders in the game. Can see all settlements in the beginning, and can build sky passages to "teleport" over the map.
Zeus: Infantry does bonus damage vs buildings. Collects favor faster, stronger heroes. Deadly mythic army against non-greek due to myrmidons and colossus spam (which can even survive quite well against the egyptian priests). Has many options when it comes to tactics, including rushing with infantry and minotaurs, raiding with centaurs, booming to mythic for uber army, etc etc. Also has bolt which is nice on water maps espescially, since you can bolt the dock builder, so your enemy needs to have at least 2.
[This message has been edited by Caboose_Nor (edited 07-25-2007 @ 07:27 PM).]