mansa: the wheel + mining is the ultimate combo for rushing a neighbour with axemen as early as possible, after which you can simply enjoy two of the most powerful traits in the game. he also has a pretty nice UU/UB.
ragnar: agressive for (early) warfare, then financial for a tech lead, then chemistry/steel on water maps. still being able to build his UU when you have chemistry/grenadiers is almost too much. grenadiers with amphibious and city raider I/II = ouch. cheap drydocks means you can build a shitload of frigates to support them too.
alexander: philo/SE + agressive makes for a really fast start. his UB is nice - makes a pretty weak building useful and construction is a nice tech to beeline for - , and i think his UU is often underrated. the free combat I it gets means its only needs 5 xp instead of 10 for the formation promotion; which seems to make them last forever.
other than that, i particularly like augustus, shaka, wang kon, frederick, mehmed... (emperor/immortal, epic)
ragnar: agressive for (early) warfare, then financial for a tech lead, then chemistry/steel on water maps. still being able to build his UU when you have chemistry/grenadiers is almost too much. grenadiers with amphibious and city raider I/II = ouch. cheap drydocks means you can build a shitload of frigates to support them too.
alexander: philo/SE + agressive makes for a really fast start. his UB is nice - makes a pretty weak building useful and construction is a nice tech to beeline for - , and i think his UU is often underrated. the free combat I it gets means its only needs 5 xp instead of 10 for the formation promotion; which seems to make them last forever.
other than that, i particularly like augustus, shaka, wang kon, frederick, mehmed... (emperor/immortal, epic)
), and his aggressive trait lets you build it in a heartbeat. This goes well with quick and easy expansion, and though I didn't get to use the Impi (no copper/iron until after knocking off my first civ), they are obviously great scouts if nothing else! 
