Well first off kudos to the first original designers, which I believe includes Tesseract, Hank, Gordon and others, for Empires, the guys who made the included campaigns like Patton's. Sure, they were actually paid in coffee to design, but they're still great campaigns. Two best interests in any scenarios for me is story and gameplay, and they definitely delivered in the story.
Otherwise, Mechstra made a fine fun Volga campaign. Gameplay was done very nicely and highly polished, except maybe the artillery piece Ex-t has proven his salt, time and time again and can dish out a fun piece fastest than anyone I've ever seen.
Mob made the most Forum Party played multiplayer scenarios though it's impossible to have gameplay or story in them, they're still some of the best for Empires.
_o0XxX0o_ has provided countless insight and newspieces for Soc, I can only wonder where he keeps pulling out new tricks.
No doubt many others, and there're still a few best of EH that I have yet to play. Maybe, I should do that right now actually.