The Rules we use:

Pre 1400:
To the Strongest (Ancient) 15mm/28mm
Classical Hack (Ancient) 28mm
Impetus (Ancient) 15/28mm
Saga (Dark Age) 28mm

1644 (ECW)
Pike Hack (ECW)

Napoleon at war (Men at war) 15mm
Fire and Fury (ACW) 15mm
Regimental Fire and Fury (ACW) 15mm/28mm

1900-Present Day:
Blitzkrieg Commander (WW2)
Bolt Action (Warlord games WW2)  28mm
Battlegroup: (WW2) 15mm/20mm
Coldwar Commander (Modern 2mm) 
Force on Force (Modern) 20mm/28mm
Flames of War (WW2) 15mm
Team Yankee (Coldwar) 6mm/15mm

Skirmish Sangin (20mm Modern)

Future Wars:
X-wing (Star wars)

And many More