Often overlooked, yet interesting even if it's just because it was a logistical masterpiece by the russians:
The battle for Manchuria, commencing 9th of August 1945 between the Soviet Union and Japan was one of, if not the largest single battle in WWII (operation Barbarossa by the germans was split on three seperate theatres, north, center and south) featuring:
On the russian side:
1,500,000 men
26,000 guns
5,500 tanks
3,800 aircraft
Against the japanese:
710.000 men
5,300 guns
1,100 tanks
1,800 aircraft
Needless to say, the japanese lost that battle. In less than two weeks they lost 80,000 killed, 20,000 wounded and 594,000 men taken prisoner by the russians.