no offense meant, but monster pops seem alittle..... BLAH
What about something ala Galactic Civilizations, where when you explore you get a chance of building a random unique wonder (or perhaps a unique tech)... But there is a catch: You have a choice between making a good, neutral, or evil version of it.
An example would be a magic mind control device.
Good civilizations: using it against members of our faith would be evil! We must use it as a means to convert the enemy into seeing the "error of their ways". Provides nationwide culture bonus and worldwide unhappiness.
Neutral: What an interesting way of making money! Provides +1 free trade agreement and bonus cash per city.
Evil: What an effective way to abuse our people! Provides small bonus of all city benefits (food, production, cash, etc)
Either have the civilization decide before or after they can see what type they could get. Depending on which moral choice they make, their alignment will change in that direction.
You could implement a unique wonder by having 3 unique techs per possible event.
One of the biggest things I liked about Galactic Civilizations was these random moral choices!
It would definately make finding an ancient temple exciting.