We've discovered a precursor factory that could be used to increase production. The problem is, anyone who enters will die from mysterious causes. What do propose?

Good: Keep our men out of there. (No change)

Neutral: Send in only volenteers (4% bomus to production)

Evil: How many times do I have to tell you? People are a RENEWABLE resource! (8% bonus)

You just gotta love the evil point of view.

You can see all of them in Program Files\Stardock\TotalGaming\GalCiv2\Data\English\Events.xml

there are two types of event. the one's you've been describing are the ethical events, which as mikeswi stated, you can see the full list for in events.xml. you can even create new ones for a mod. the base game has too many for me to try and list.

these events only occur before you've researched xeno ethics (since they effect your alignment, they stop with xeno ethics because that tech fixes your alignment to whatever you chose).

the second type of event is more elusive, and i can't remember where to find their programming. these are "spice up the game" events. they can be fairly interesting. here's ones i can think of.

-Archaeologists on some planet discover a precursor artifact that doubles the planet's base quality.
-Archaeologists in some system discover a precursor artifcat that causes every PQ-0 planet in a certain radius of sectors to go up to some value (i've seen 4, 7 and 12... this event can totally change the course of a game).
-During negotiations, one of your empire's unionists assassinates another empire's leader, causing your civs to go to war.
-A good or evil race switches to the other side.
-Archaeologists discover a precursor ranger or corvette.

some of the events seem sensitive to certain aspects of how the game is going, such as:
-A waining civilization discovers a precursor artifact that causes them to grow more powerful every turn (all their ability bonuses get +1% each turn - only happens to weak civs).
-An empty system is colonized by a new minor race (doesn't occur if minors are disabled - are they minor races because everyone's under 18?)
-A planet in an empire splits off to form the ILP or something like that, the indi legue of planets (also doesn't occur if minors are off)

I remember reading in a file somewhere something about an alliance war. i think it'd be possible that this event only occurs when there are two sets of alliance treaties going, but i've never actually seen an event like this.

I got the "Colonies for Entire Tech Tree" event the last game I played, but was unable to actually do anything in response. It popped up at the start of the New Turn processing, got dismissed by the GNN and other event screens, and by the time I was able to contact the minor race in question, they just looked at me like I was crazy when I tried to trade with them.

I like the one where your citizens start playing Pokemon and your options are:
Good: That's horrible, stop this animal abuse at once! (-Morale)
Neutral: Put regulations on Pokeballs and make sure they don't fight to the death.
Evil: Woohoo! I'm up to 80 species! (+Morale)

I got one in my last game where the Arceans got nearly a thousand precursor corvettes named Vengeance (they spawn based on map size, I was playing Gigantic). They weren't any danger to me (I had zero-point armor on all my ships by then), but they used so much memory that I had to shut down my game and reload from an earlier save point to be able to continue playing! I think the AI has definitely improved in 1.2--it's bypassing the player's civilization and going straight for the computer itself!