DarkSchneider
King
I am just as tired as the rest of you when cities that I conquer enevitably revert to the enemy. Even when the enemy is weak and pathetic and could never take back said city in a million years on its own
I haven't figured out how to prevent it, but here is what I have observed:
Keep them happy - Seems like an obvious factor, as does WLTKD, it is rare for a city celebrating to revert during that turn.
Keep a lot of units in the city - Not sure about this, but cities seem a lot less likely to revolt if they have a large number of defensive units guarding them.
Keep an army in the city - It is even rarer for the city to depose you if an army of strong units exists in the city. The only downside to this is if they do depose you, you stand to lose a whole lot more.
Get your own citizens in there - Or at least take some captured workers from a long dead Civilization or a Civilization you are at peace with.
Build culture - My guess is that some of the checks factor in the cultural strength the city was at before you conquered it, vs. the current culture. Anytime a city flips it will go back to the culture rating it was at with the previous Civ.
Rush build Improvements - This also builds culture and keeps people happy
Stick with Democracy - I tend to lose most of my cities during periods of Anarchy and Despotism, although this could be related to the happiness factor
If all else fails - Take all of your units out, and sell the city to the highest bidder
Feel free to add to this list...

Keep them happy - Seems like an obvious factor, as does WLTKD, it is rare for a city celebrating to revert during that turn.
Keep a lot of units in the city - Not sure about this, but cities seem a lot less likely to revolt if they have a large number of defensive units guarding them.
Keep an army in the city - It is even rarer for the city to depose you if an army of strong units exists in the city. The only downside to this is if they do depose you, you stand to lose a whole lot more.
Get your own citizens in there - Or at least take some captured workers from a long dead Civilization or a Civilization you are at peace with.
Build culture - My guess is that some of the checks factor in the cultural strength the city was at before you conquered it, vs. the current culture. Anytime a city flips it will go back to the culture rating it was at with the previous Civ.
Rush build Improvements - This also builds culture and keeps people happy
Stick with Democracy - I tend to lose most of my cities during periods of Anarchy and Despotism, although this could be related to the happiness factor
If all else fails - Take all of your units out, and sell the city to the highest bidder

Feel free to add to this list...