Civilization: Call to Power/Wonders

Labyrinth
Gives free caravans.

This wonder is a must-have. Having free trade-routes means you can generate a lot of gold very quickly, essential for developing a strong military and progressing along the tech-tree. Couple this wonder with the Sphinx (75% reduction of military support costs) the East India Trading Company (+1 ship movement, 20 gold per foreign trade route crossing water) and The London Exchange (no city improvement maintenance costs) and you're in a very strong position.

London Exchange
Eliminates maintenance costs

Sensorium
Eliminates unhappiness caused by pollution and more importantly overcrowding.