Tales of Middle-Earth is an ambitious mod that seeks to bring the world of Lord of the Rings not to some modern strategy game like Total War, but to one a little older, one that's definitely earned the title of a classic: Age of Empires II.
The mod's called Tales of Middle-Earth, and while it's technically still in beta, you can download it and try it out. While some vestiges of the original game remain, a lot of effort has been made to convert most units to those found in the books/films, and as you can see there's even Sauron and trolls.
(view original) [ModDB]