Yes, I want all the mega events present in GalCiv2, and much more...

I also suggest to add a button, somewhere in the interface of the game, so the player can trigger a random mega event to "shake up the game", just like it is possible to trigger a disaster in Sim City (the first one)(I only played the first); it would be great.

Perhaps with the possibility of a setting, per example, trigger a random mega event in the next 50 turns.

Bah, I hated the Daggers and the Plague. Its for that reason alone I turned them off. Here I am ruler of a Galactic empire and bam, I lose what 1/2 of all my planets even including Earth? WTF?

If the loss was coded to be 'outer rim' ones from the home planet I would be ok. 

There was a plague but you never knew how it worked you just had to research the cure. I would be ok as long as the planet showed up on a notification or on the map with a big glowy blue (contagious) on it. I like it traveling along trade routes but those are so few in the game sometimes that i doubt the spread would affect much. On Excessive you can have dozens of planets and only 3 or 5 trade routes by turn 180. 

Ah yes the Vegans. They indeed should make an appearance mid to late game and come 'armed to the teeth' so initially they cannot be crushed but 'take a while'. 

Yes please. But what about a Peacekeeper like event? I didn't play GalCiv II, so I don't know if it would be good or bad.

We need events that change the gameplay or that at least have some noticeable impact on it. It would help immersion and role playing, which I feel that is currently missing in GalCiv III. I have been thinking of other events that could create new factions, such as a separatist event that creates a new faction out of planets with low approval.

For me the best thing about the GCII mega-events was that they could be turned off. 

When I have been busting my ass for a couple of hundred turns to build an empire, I don't want some BS wrecking it. That is too much like real life for me.

(Go ahead and call me a pussy)

Several new mega events should be added, in addition to the old ones from GCII:

• A new religious movement has arisen in the galaxy, valuing austerity and simple living and generally shunning the modern and galactic way of life. The most committed members of this movement have embarked on journeys to hitherto unknown sanctuary worlds (~5% of the galactic population starts a major civ and creates transports leaving from core worlds of existing divs, moving to new worlds with strong boosts to Influence, Tourism (pilgrimage destinations), and Planetary Defense (reclusive), but with sharply lower military and social production. This civ would have powerful Diplomatic, Influence, and Tourism technologies to be traded with, or its rich sanctuary worlds could be conquered.)
• The galaxy has recently been subject to a bout of coup plotting. Corrupt generals in a number of starfleets have commandeered vessels with the intention of occupying homeworlds and forcing a change in government. (Each major civ will have a corresponding minor civ, named "[civ name] Coup", armed with transports and various vessels aiming for their homeworlds. If a successful invasion of the homeworld takes place the government system will be reverted back to Imperial and secondary revolts will take place with a probability of 1-(influence percentage on planet * approval rating on planet), with the probability then halved for Benevolent civilizations and doubled for Malevolent ones. Revolting planets will start their own major civs, which can influence-annex each other. Additionally, the player will lose control over the home world for 10 turns, with this amount doubled for malevolence and halved for benevolents.)
• The galactic economy, trade system and tourism sector are booming, while colonization of previously uninhabited regions is continuing apace. Unfortunately, with this phenomenal growth comes a massive rise in piracy. (Pirate shipyards form on the periphery of all empires empire, guarded by pirate vessels.)
• Bolstered by undesirable governmental policies, the people of the galaxy decide to take matters into their own hands and stage revolts. Work stoppages, riots, and outright rebellion begin to grip known space. (Planet productivity after all bonuses will be multiplied by the planetary approval level for 10 turns. Probability of revolt same as above.)

EDIT: Some minor fixes that gives these ideas more coherence, does not change the function of the mega events.

no its my internet history and you cant have it

Yes, I should correct that. It should be a major civilization. As for Politics, I believe that the government techs are becoming unlocked in Beta 6.

I appreciate the support for these ideas; Mega Events should become a part of the game and add some depth to playing, especially in the mid-to-late game phases where otherwise you would be doing nothing but gearing up for final victory.