Lets have some thoughts on what settings give the best/fairest games (I know the dice throw a spanner in the works)
I will start.
For 1 v1 and Team Games
Polymorphic - I feel that Poly is a must. 4s or 3s depending on the map size and dynamics
No Spoils - Flat rate and Escalating create too much additional luck regards what cards you get and dice luck to take a card.
Trench - Once again to mitigate for the dice (most of these settings are for this reason) as a player cant run amok due to a lucky streak.
No Fog - I appreciate the attraction to it but going through logs to guess is a hinderance and seeing what the other player is doing avoids lucky choices.
Parachute - Not only does it mitigate against dice but it means you can use your troops even if you have a poor drop. It also adds an element of strategic play as to where and how you move your troops.
Rounds - I like no limit but in tournaments it can be used to create fair draws
For multi player games - These are really what Risk is about even though most games in CC are 1 v1.
(The world needs a great strategic multi player game that removes most of the luck. CC is not this.)
No Spoils - There is nothing worse than having painstakingly created a great position only to have it wiped out by several players cashing in the same round. It is a gamble to calculate who might have what.
Run (No trench) - In multi player games it is often necessary to move over several territories in a single turn
Sunny (No Fog) - Once again the laborious nature of going through the logs second guessing where players might have dropped
Parachute - Given the nature of the Dice and the drop I don't know why all games are not played with a parachute setting.
Rounds - None
Some food for thought.
I look forward to other players thoughts on their favorite settings.
There is no right or wrong, just opinion and preference.