I've never been on one without snack and beverage service. I suppose if it's a very short flight they might not, but I've never been on one shorter than 50 minutes.
They serve:
Snacks - Complimentary
Peanuts
Pretzels
Nabisco® Selections* (sometimes these are plane shaped crackers)
Non Alcoholic - Complimentary
Coca-Cola Classic
Diet Coke
Coke Zero
Sprite
Sprite Zero
Dr Pepper
Ginger Ale
Tonic Water
Mr and Mrs T Bloody Mary Mix
Orange Juice
Apple Juice
Tomato Juice
Cranberry Apple Juice Cocktail
Carbonated Water
Non-Carbonated Purified Drinking Water
LIFT Coffee
Coffee
Decaf Coffee
Tea
Hot Cocoa
Energy Drink $3
Monster Lo-Carb
Cocktails $5
Dewars Scotch
Jack Daniels
Wild Turkey
Tanqueray Gin
Bacardi Rum
Baileys Irish Cream
Finlandia Vodka
Canadian Club Reserve