Brandy: Apple Cider, peach or apricot syrup
Rum: Pineapple juice or syrup flavored with almond extract
Sherry: Orange or pineapple juice
Kirsch: Syrup or juice from black cherries, raspberries, boysenberries, currants or grapes or cherry cider
Cognac: Juice from peaches, apricots, or pears
Cointreau: Orange juice or frozen orange juice concentrate
Crème de menthe: Spearmint extract or oil of spearmint diluted with a little water or grapefruit juice
Red Burgundy: Grape juice
White Burgundy: White grape juice
Champagne: Ginger ale
Claret: Grape or currant juice or syrup or cherry cider
Note: to cut the sweetness of the syrup, dilute with water. Also, there are many flavor extracts, such as almond or pineapple, that can be added for interesting flavors.
Flambes or Flaming desserts:
The only substitute that might be used is a sugar cube soaked in lemon extract, then set atop a dessert and burned.
For information relating to cooking off the alcohol when using it in recipes, click on this link. You'll be suprised at how long it actually takes! http://www.ochef.com/165.htm