In 1998, StarCraft told the story of three races in conflict, and it went a little something like this... The Terrans - human colonists - are torn apart by civil war and find themselves stuck in the middle of a war between the Protoss and the Zerg. The Protoss and the Zerg are enhanced alien races given an evolutionary leg-up by a meddling super-race called the Xel'Naga.
The Protoss gained psionic powers that singularly failed to stop them from waging civil war, while the Zerg were given advanced parasitic powers, turning them into a hive-like plague, wiping out or infesting everything in their path.
It was the combat between these three very different races that was the basis of StarCraft, and it was the fine balance between their very different modes of combat that made it so breathtakingly unique. StarCraft had an elaborately constructed universe, finely tuned combat and a cracking story. It was, without crawling too far up Blizzard's arse, the greatest RTS of its time, and if you can suffer the dated graphics, it's still among the best.
By revealing the game in Seoul, Korea, the master tacticians at Blizzard chose the friendliest ground possible for their announcement. That said, it was interesting to note the tone of the crowd, after the initial hooting and cheering died down.