Initial list taken from the Save the Universe RPG.

• A secret meeting of galactic crime bosses
• A hostile takeover of a peaceful planet
• The outbreak of a great war
• A great science conference
• The trial of an infamous war criminal
• Vital treaty negotiation between hostile powers
• The appearance of a previously unknown species
• A great threat which unifies previously hostile civilizations
• The sudden destruction of an important planet
• The galactic boxing heavyweight championship