Infinite Space for Sins of a Solar Empire: Rebellion. The mod enhances the overal look and feel of the game by adding a ton of new planets and planet types, planet bonuses, rendering, tweaks and much more!
One of the, if not THE, best non-total conversion mods available for Sins. The few minor problems do not detract from the experience in the slightest, and this is a well-deserved 10/10. Fantastic work!