Star Wars: Total War
Meh ... seriously though, if set during the Clone Wars period you could have some huge battles, just look at the Battle of Geonosis in Attack of the Clones for example, that one was the biggest ground battle in the movies. And since the Star Wars universe is set on many planets, then that's maybe were the Total War series would go, for uncharted terrain. You could have the most symbolic / relevant planets of the Star Wars series, like Coruscant, Naboo and Yavin, and a couple others, and on each of them you'd have a single map. And you could build your Pirates Consortium, Republic (the Rebels), or a Galactic Empire (the Empire of course). Yay ? Nay ?
If not, then I have some ideas ...
Napoleonic: Total War
Gothic: Total War (set in a fantasy world à-la Warhammer, with fantasy-based creatures for example)
Warhammer 40,000: Total War (that one guys I am waiting for it since I heard about Rome: Total War, can't you just TRY to imagine HORDES of Greenies charging on foot at the eagerly awaiting Marines Chapter on the other side of the river filled with blood, in a foggy atmosphere ? I sure can !)