Well, SirVegeta, he started to design a reall great LotR campaign (he putted the bate version of the first level somewhere here on the forums). And then disappeared.
Now, SirVegeta, about your scenario... First things first: lags. The game is really laggy. I recommend you not to put all those orc units right from the start. Put, I don't know, no more than one hundred, and then use the spawn units trigger trick.
Then, the balance. There are far too many castles and towers actuallym kill almost all of the orcish army. And the only units I moved from one place to another are Aragorn, Legolas, and Gimli.
Well, tha map design isn't so great, but good one nonetheless. No more than four... I thin 3, because the surrounding plainc which you can actually see are not the best one's.
And the map design of Helm's Deep in particular. You wanted it to be similiar to the movie, but it isn't. It isn't so similiar to the books. First: there are far to many gates, while Helm's Deep had only one. This Helm's Deep is more similiar to Minas Tirith than Helm's Deep (of course if you wanted to follow the movie map design of the fortress...
And the last thing: never name your scenario "the best". Well, you didn't name the campaign like that, but you did named the archive "Best Helm's Deep". Because I tell you: it is not the best. I think it is the same level as King's Bob VI Helm's Deep, to be honest.
Well, this scenario isn't so bad, but there are many things to improve!