I won't claim that my mod is the best, but its pretty much complete with exception of a new map currently in the works.
Improved AI on strat and battle level
VnV fixes and tweaks
Improved 2H animations
Larger and more balanced AI armies
Active rebels (as active as one can make them)
Less agent spamming
Stronger gunpowder and aztecs

There more to it of course, but for the most part I've tried to keep it simple and close to the main game rather than focus on flashy new unit skins or new factions.

Give it a try if you like