1)
Askia: River Warlord -- The best super early rush in the game. All that money gives them 2 extra horseman, for a truly unstoppable horde. Also a good increase in loot for cities you raze further feeds the horde.
2)
Alexander: Hellenic League -- Can afford to ally with 3x as many city states for the same price others can ally with one over time. Large boost across the board.
3)
Cyrus: Achaemenid Legacy -- On high lvls (Emperor+), you can parlay this ability to stay in a constant golden age for for around 60 turns, which can allow you to get over the hump of finishing off the second continent.
4)
Wu Zetian: Art of War -- You get extra 15% from the generals and more golden ages from the spare generals that pop at higher rates. You can save the generals to string together an extended golden age the same as Cyrus, and for the same purpose.
5)
Oda Nobunaga: Bushido -- You'll seldom take a lot of dmg taking over the first continent, but on the second bushido can really really help! The downside is that it works better if you rush swords instead of horses to take advantage of the UU, which is harder to pull off.
Honorable mentions:
Ramesses: Monument Builders -- If your going to waste time building a monument these are your guys. Can use GL for beeline strategies.
Bismarck: Furor Teutonicus -- Good early defense with extra units from barb pops, so you don't have to worry while you build horseman. Little extra gold helps too early.
Somewhat Honorable mention:
Napoleon: Ancient Régime -- Quicker SPs.
Ramkhamhaeng: Father Governs Children -- Essentially 1.5x the city state for the price of one.
Dishonorable mention(utter rubbish):
Gandhi: Population Growth -- Good for late game expansion, but late-game is soo unimportant...
Augustus: Glory of Rome -- Their UUs are good, but horseman are better, so...
Washington: Manifest Destiny -- Saves a descent bit of gold, but not enough to matter early on.
Catherine: Siberian Riches -- Selling resources brings a bit of small coin. Horses are to common to be an issue 90% of the time, so resource limitations rarely come into play with other civs.
Elizabeth: Sun Never Sets -- AI rarely builds a navy
Harun al-Rashid: Trade Caravans -- +1 gold per trade route...really...thats it?; gameover before oil makes impact
Montezuma: Sacrificial Captives -- Has to kill a unit every turn to get half of what the French get for doing nothing.
Suleiman: Barbary Corsairs -- Waste time building a boat to get units I will disband for small coin. Um...no thank you...
Hiawatha: The Great Warpath -- They're kidding right...it doesn't even work outside your own territory
