Here're my two cents, if you want them:
Some WWII themed ones:
Invasion of Normandy(D-Day or something of that nature)
Battle of the Bulge(Last German counter-offensive of the war, major battle. you could do the Maginot Line, a seemingly impenetrable line of French forts)
A Spanish map- Surprisingly, there are no big ones
An Aussie map- Here's a good pic: