Let us gather a mighty hoard of adventure and campaign ideas, compressed to what was most important about them.

From me:

Tides of Homeland: Four heroes with no place to call home come together to stop a mind flayer's attempt to save his people by destroying all other races. The mind flayer seeks an ancient magic to drive all the world mad with rage, and after his first defeat he secrets himself into the mind of one of the heroes, Harley, a lost and emotionally vulnerable woman whom he uses to further his plots. Only the friendship formed within the group can free her soul and save the world.

The Fall: The son of a demon summoner discovers that his mother's dying bargain was to trade his soul for the death of a paladin order that had wronged her. The problem is, the demon never fulfilled its bargain, and the son finds himself in the middle of an infernal game. Temptations abound -- power, fame, and vengeance -- but even the corrupted can still fight a greater evil.

Winds of Change: A group of adventurers hire on as bodyguards for Vidania, an air mage apprentice on a pilgrimage to find places of great aeromantic power. In their journeys they discover an ancient air mage who was thwarted many times in the past is attempting to dissolve the world into the elemental plane of air. Will the winds blow in the party's favor, or has this villain's luck changed?

Scourge of the Burning Sky: As a world-spanning empire falls, generals and archmages scramble for power, threatening to destroy the world amid their warfare. Refugees from the empire assemble in a resistance and one by one take down these new emperors, walking the line between saving the world, and becoming its next tyrants. All the 'ancient artifacts' that might exist in a fantasy setting are created and used in this war, but the most powerful force is held by a would-be ally, hidden in ever-reflecting secrets.

The Graveyard of Steel: Three creators of a steamtech doomsday device flee to keep their masterpiece from destroying the world. Heroes could have discovered the true conspiracy and saved the world, but the best hope for salvation is a group of criminals, murderers, and madmen. The world (not to mention the GM's sanity) is doomed.