Well, at least for me the Chinese looks like my best shot to win at Deity.
Early game - industrious workers build irrigation network, allowing my cities to grow fast, rush building/killing citizens.
Early mid game - get iron, horse resouces and Chivalry, build huge army of Riders, which beat up on Immortals, War Elephants, Legions, Impis, and Samarai, not to mention swordsmen and pikemen, when veteran or elite. Workers go back and mine to ramp up production.
Fairly soon (militaristic civ) you get a great leader. Use the first to build the Foridden palace deep in enemy territory -or- create an army of veteran Riders (save the elites for more leaders). After the first army victory you get another small wonder (don't remember the name) that increases your chances of generating leaders.
Now you will get a great leader about 1/10 elite battles. Use them to rush build every wonder near the front lines, expanding your culture and making conquest easier.
Late game - don't know yet

This strategy has worked at lower difficulty and I'm about to try it at Deity. I will have to decide whether to go for military victory at this point or hunker down with research.