Starcraft:
As Terran, I'd get a wall of tanks, coupled with marines and wraiths, and possibly a science vessel or two for detection. You set the tanks to siege mode, then unsiege them one at a time and inch them forward. The tanks easily destroy any buildings you come across, and can provide a shot or two as enemy troops try to counter. If they get too close, they meet a small army of marines and wraiths. Any attempts to sabotage the tanks via stealth can be thwarted by the science vessels. Easy win.
I think everyone is acquainted with the zergling rush. Fairly straightforward. Build rows of hatcheries and spawn as many zerglings as physically possible, and then send 'em all to the enemy. Chances are he hasn't built a solid defense yet, and is easily over-run.

Age of Empires 2 (with expansion)
You build an army of battering rams and infantry. Upgrade them to the fullest, then load the rams with the infantry. Send them in. Just concentrate on destroying the buildings. Any battering ram that is destroyed spawns the infantry you set inside, who will proceed to attack the defenders. Rams loaded with infantry move faster, too. An army within an army, really.

Tanks are easily destroyed with Zerg Queens and spawing broodlings. A couple of scourges to blow the observers up and then lurkers are great for an early attack on terrans and Protoss without any detection devices. If time allows it, defilers are great with all technologies, with clouds and hydras under it to get carriers or even guardians. With Consume defilers regain energy, and the blood rain slowly destroys buidlings and lowers enemies' life points.