Third Age - Total War is a total conversion for 'Medieval II: Total War - Kingdoms Expansion' that brings you into the world of Middle-earth.
This mod is expertly put together, very few bugs (and the few bugs there are are frequently fixed with regular patches).
Fantastic textures and unit models, brilliant map.
However; the thing that truly impresses me is the extent to which the team have gone to to remain true to the lore of Lord of the Rings. Detailed unit information and mini-custscenes for important places (The Shire, The Black Gate, Minas Morgul, Moria, Edoras, Minas Tirith etc).
Truly fantastic mod, one of the best I've ever seen.