I'm with gidza, Starcraft!
Opening scene, 6 terran tanks rolling through alien tundra, 40 or so soldiers trailing the tanks with 10 or so leading the tanks as scouts.
Suddenly 3000 zerglingz unburrow and massacre the entire lot in less than 50 seconds.
The terran panic and call for help, the protoss answer the call. The protoss are also having problems with the zerg in their own homeworlds, and they natrually hate zerg, but, it's not in their nature to form alliances with anybody ...
The next scene opens up on the main encampment, camera flying over 2000 "sprinting" zerglings all being mowed down by frantic gunfire from the men in the fortified dugouts, every now and then a bright flame shoots from the dugouts, turning zerglings into fireballs. The camera flies further back, and we see the siege tanks firing together, and the camera follows the shots as they land, clearing massive holes in the sea of zerglingz.
Then theme it like braveheart and we have a winner, with sequals through the nose, and a series. But, the wars and the balance starcraft managed to attain must be kept alive.