I've posted a couple of random events ideas in this thread:
http://forums.civfanatics.com/showthread.php?t=240059
Fell free to use them.
EDIT: I'll repost it here for your convenience:
“Money Quest”
Build X Markets. Extra reward if Colossus.
1: Extract taxes from merchants: Lump sum of

(about 500)
2: Just listening to foreign merchants is helpful in gathering intelligence: +2

for Markets
3: With solid base we can expand our trade network: Extra trade route in every city.
“Stargazer”
Build X Observatories. Extra reward if University of Sankore.
1: Detailed star charts help in navigation: +1 movement for Water Units.
2: Attract new scientists: +2

for Observtories.
3: Great Scientist is born.
“Food Storage Quest”
Build X Granaries and X Aqueducts. Extra reward if Hanging Gardens.
1: We are ready to expand: Gain 2 (1?) Settlers.
2: Food for the masses: +1

for Granaries.
3: Population boom: Extra pop in every city (with a granary?)
“Hospital Quest”
Build X Hospitals.
1: Our citizens apreciate highest standards of medical care: +2

and +1

for Hospitals.
2: Decipher secrets of human genome: Discover Genetics.
3: Start nation-wide eugenics program: +1

and +3

(greast scientist) for Hospitals.
“Jail Quest”
Build X Jails. Extra reward if Pentagon.
1: Tap forced labor: +2

for Jails.
2: Curb corruption and inneficiency: -10% maintance for Jails.
3: “The Dirty Dozen”: Great General (Great Spy?) is born.
And some other random events:
“Ambassador”
Trigger: Contact with an AI that has contact with a second AI unknown to human player.
1: Make contact with that second AI.
“Suburbs”
Trigger: Big/unhealthy city with cottages.
1: City loses 1 pop. Some cottages gain 10 extra turns of growths.
“Migration”
Trigger: City #1 with high health/culture and a city #2 with low health/culture.
1: City #1 gets +1 pop while City #2 loses 1 pop.
“Eclipse”
Trigger: Ancient (and Classical?) Age and city with State Religion.
1: We are doomed!: Pay nothing. City revolts for 1 turn.
2: Calm the citizens: Pay some

. Nothing happens.
3: We must appease the gods: Pay more

. City gains state religion temple.
“Soda Water”
Trigger: Sugar resource and city with aqueduct.
1: Quite a refreshing drink. Let’s call it “coke”: +3

for Aqueduct in that city.
“Finest Breed of Horses”
Trigger: Horses and city with stables.
1: Sell them: Lump sum of

. (about 150)
2: They will form the core of royal/national guards: Pay some

. Gain most modern cavallery unit with free morale promotion.
2nd EDIT:
- Third reward option for Hospital Quest could be a

multiplier as well. Like +25%

. I don't have any idea for matching wonder prereq however.
- Why does your Controversial Philospher give Great Enginner/Spy? Wouldn't regular spy/engineer specialist suffice?
And some more event:
"Captain Meires' Pirates"
1: One of your non-cargo ships is given to barbarians and receives Navigation I & II promotion.
"Customs House Quest"
Build X Customs Houses.
1: Redesign our ships to transport more cargo: +1 cargo for transport ships.
2: Less than respectable means of profits:

from plundering sea trade routes is doubled.
3: Assing goverment agents to Customs Houses: You can hire up to (1?) 2 spies specialists in Custom Houses.