Zara Yaqob of HRE. Rathaus + ORG means a massive empire, settler spam and CRE to make the borders expand from the word go. I took over half a pangea map without a war on Prince doing that.

I started near the center.
I played Lincoln of Egypt once, was quite fun.
Also Tokugawa of Ethiopia, spammmmmm with those Oromos!
And Churchill of Native America. Those archers are mean! CHA for the cheap promos, PRO for the free promos and the +3xp from totem poles to really boost them. You should have seen my armies when I upgraded the 40 archer spam to grenadiers

Madness!
Right now I'm playing as Pericles of Arabia. CRE for fast Madrassa, then PHI for fast GP spam. Started on a flood plain river, 4 specialists from one building makes for a lot of GP points! Lightbulb philosophy with a scientist, academies, several settled scientists and prophets, constitution/representation sling from delaying liberalism until after nationalism [missed pyramids due to settler spamming and no stone] [while keeping a check to see none of my rivals had even got to paper, nevermind education].