I think mine would probably be something like Huns, Spanish and Slavs. Spanish have great late-game cavalry, fast building, gold-free blacksmith, cannon galleons that don't fire sluggish balloons and one of the scariest unique units in the game (though my brother keeps reminding me they're pretty weak early game...), Huns don't have to worry about housing population, have great horse archers and a UU I think is underrated, while Slavs have solid infantry, cheaper siege (got to love those onagers), faster farming (great however you slice it) and, again a great cavalry UU that's basically a Teutonic Knight on a horse. Good cavalry tends to be something I gravitate to in some form or another.
