Silica_Pathways
King
A list, that i made for myself, but probably you'll find it useful too 
Summary of scenarios suggested for C3C multiplayer:
American Civil War
* for 2 players
+ based on historic events
+ lots of new stuff
- download size
The Battle of Iwo Jima
* for 2 players
+ based on historic events
+ some new stuff
- download size
Barbarossa: The War in the East 1941-1945
* for 2 players
+ based on historic events
+ lots of new stuff
- download size
Bosnian civil war 1991-1995
* for up to 5 players
* 2 alliances
+ based on historic events
+ small download size
- no new stuff
2nd British Civil War 2012
* for up to 4 players
* 2 alliances
* based on realistic setting, fictional events
+ small download size
- no new stuff
Converted Civ2 Rome scenario
* for up to 7 players
* 4 alliances
+ based on historic events
+ small download size
- no new stuff
Iran-Iraq War
* for 2 players
+ based on historic events
+ some new stuff
- dowload size
Island Conquest
* for up to 8 players
* 4 alliances
+ lots of new stuff
- download size
King Of The Hill
* for up to 8 players
+ small size
- almost no new stuff
Korean War 2005
* for up to 4 players
* 2 alliances
+ based on realistic setting and possible events
+ small download size
- no new stuff
Lesser Antilles Islands
* for up to 4 players
* 4 alliances
+ based on historic events
+ some new stuff
- download size
The Opium War 1840-1895
* for up to 7 players
* 4 alliances
+ based on historic events
+ small download size
- no new stuff
Portuguese Colonial War: Angola 1961-74:
* for 2 players
+ based on historic events
+ lots of new stuff
- download size
Russian Japanese War
* for up to 7 players
* 1 alliance
+ based on historic events
+ small download size
- no new stuff
The Three Kingdoms
* up to 3 players
+ based on book
+ some new stuff
+ different campaigns available
- download size
Typhoon of Steel
* for up to 5 players
* 2 alliances
+ based on historic events
+ lots of new stuff
- download size
Not all scenarios that should are in the list, but i'll update it, when i can.
Unfinished and scenarios with serious bugs won't be added to list.
Only Civilization3: Conquests scenarios are/will be on the list.
Post suggestions about scenarios, that should be included or excluded and feel free to correct me, if i had mistaken somewhere.
Currently there are 16 scenarios in the list.

Summary of scenarios suggested for C3C multiplayer:
American Civil War
* for 2 players
+ based on historic events
+ lots of new stuff
- download size
The Battle of Iwo Jima
* for 2 players
+ based on historic events
+ some new stuff
- download size
Barbarossa: The War in the East 1941-1945
* for 2 players
+ based on historic events
+ lots of new stuff
- download size
Bosnian civil war 1991-1995
* for up to 5 players
* 2 alliances
+ based on historic events
+ small download size
- no new stuff
2nd British Civil War 2012
* for up to 4 players
* 2 alliances
* based on realistic setting, fictional events
+ small download size
- no new stuff
Converted Civ2 Rome scenario
* for up to 7 players
* 4 alliances
+ based on historic events
+ small download size
- no new stuff
Iran-Iraq War
* for 2 players
+ based on historic events
+ some new stuff
- dowload size
Island Conquest
* for up to 8 players
* 4 alliances
+ lots of new stuff
- download size
King Of The Hill
* for up to 8 players
+ small size
- almost no new stuff
Korean War 2005
* for up to 4 players
* 2 alliances
+ based on realistic setting and possible events
+ small download size
- no new stuff
Lesser Antilles Islands
* for up to 4 players
* 4 alliances
+ based on historic events
+ some new stuff
- download size
The Opium War 1840-1895
* for up to 7 players
* 4 alliances
+ based on historic events
+ small download size
- no new stuff
Portuguese Colonial War: Angola 1961-74:
* for 2 players
+ based on historic events
+ lots of new stuff
- download size
Russian Japanese War
* for up to 7 players
* 1 alliance
+ based on historic events
+ small download size
- no new stuff
The Three Kingdoms
* up to 3 players
+ based on book
+ some new stuff
+ different campaigns available
- download size
Typhoon of Steel
* for up to 5 players
* 2 alliances
+ based on historic events
+ lots of new stuff
- download size
Not all scenarios that should are in the list, but i'll update it, when i can.
Unfinished and scenarios with serious bugs won't be added to list.
Only Civilization3: Conquests scenarios are/will be on the list.
Post suggestions about scenarios, that should be included or excluded and feel free to correct me, if i had mistaken somewhere.
Currently there are 16 scenarios in the list.