How do the caffeine levels in coffee, tea, and soda compare?

Question

I realize it varies from type/brand to the next, so feel free to be as detailed or as general as you see fit.

Answer 1

Coffee is the highest.

Here's 2 lists from highest to lowest:

Caffeine Content Of Popular Drinks

12-ounce beverage milligrams

Red Bull (8.2 oz) 80.0
Jolt 71.2
Pepsi One 55.5
Mountain Dew 55.0
Mountain Dew Code Red 55.0
Diet Mountain Dew 55.0
Kick Citrus 54.0
Mellow Yellow 52.8
Surge 51.0
Tab 46.8
Diet Coke 45.6
Diet Coke with Lemon 45.6
Diet Coke with Lime 45.6
Diet Vanilla Coke 45.6
Shasta Cola 44.4
Shasta Cherry Cola 44.4
Shasta Diet Cola 44.4
RC Cola 43.0
Diet RC 43.0
Dr. Pepper 41.0
Diet Dr. Pepper 41.0
Diet Sunkist Orange 41.0
Mr. Pibb 40.0
Sugar-Free Mr. Pibb 40.0
Red Flash 40.0
Sunkist Orange 40.0
Slim-Fast Cappuccino Delight Shake 40.0
Ruby Red 39.0
Storm 38.0
Big Red 38.0
Pepsi-Cola 37.5
Pepsi Twist 37.5
Diet Pepsi 36.0
Wild Cherry Pepsi 38.0
Diet Wild Cherry Pepsi 36.0
Diet Pepsi Twist 36.0
Aspen 36.0
Coca-Cola Classic 34.0
Coke C2 34.0
Cherry Coke 34.0
Lemon Coke 34.0
Vanilla Coke 34.0
Diet Cherry Coke 34.0
Snapple Flavored Teas (Reg. or Diet) 31.5
Canada Dry Cola 30.0
A&W Creme Soda 29.0
Nestea Sweet Iced Tea 26.5
Nestea Unsweetened Iced Tea 26.0
Barq's Root Beer 23.0
A&W Diet Creme Soda 22.0
Slim-Fast Chocolate Flavors 20.0
Snapple Sweet Tea 12.0
Lipton Brisk, All Varieties 9
Canada Dry Diet Cola 1.2

8-ounce Beverage milligrams

Coffee, Drip 115-175
Coffee, Brewed 80-135
Coffee, Espresso (2 ounces) 100
Coffee, Instant 65-100
Tea, iced 47
Tea, brewed, imported brands (avg.) 60
Tea, brewed, U.S. brands (avg.) 40
Tea, instant 30
Tea, green 15

Answer 2

8-ounce Beveragemilligrams
Coffee, Drip 115-175
Coffee, Brewed 80-135
Coffee, Espresso (2 ounces)100
Coffee, Instant 65-100
Tea, iced 47
Tea, brewed, imported brands (avg.)60
Tea, brewed, U.S. brands (avg.)40
Tea, instant 30
Tea, green 15
Hot cocoa14
Coffee, Decaf, brewed 3-4
Coffee, Decaf, instant 2-3

Soft Drinks
12-ounce beveragemilligrams
Red Bull (8.2 oz) 80.0
Jolt 71.2
Pepsi One55.5
Mountain Dew 55.0
Mountain Dew Code Red 55.0
Diet Mountain Dew 55.0
Kick Citrus 54.0
Mellow Yellow 52.8
Surge 51.0
Tab 46.8
Diet Coke 45.6
Diet Coke with Lemon 45.6
Diet Coke with Lime 45.6
Diet Vanilla Coke 45.6
Shasta Cola 44.4
Shasta Cherry Cola 44.4
Shasta Diet Cola 44.4
RC Cola 43.0
Diet RC 43.0
Dr. Pepper 41.0
Diet Dr. Pepper 41.0
Diet Sunkist Orange 41.0
Mr. Pibb 40.0
Sugar-Free Mr. Pibb 40.0
Red Flash 40.0
Sunkist Orange40.0
Slim-Fast Cappuccino Delight Shake 40.0
Ruby Red 39.0
Storm38.0
Big Red38.0
Pepsi-Cola 37.5
Pepsi Twist 37.5
Diet Pepsi 36.0
Wild Cherry Pepsi 38.0
Diet Wild Cherry Pepsi 36.0
Diet Pepsi Twist 36.0
Aspen 36.0
Coca-Cola Classic 34.0
Coke C2 34.0
Cherry Coke 34.0
Lemon Coke 34.0
Vanilla Coke 34.0
Diet Cherry Coke 34.0
Snapple Flavored Teas (Reg. or Diet) 31.5
Canada Dry Cola 30.0
A&W Creme Soda 29.0
Nestea Sweet Iced Tea26.5
Nestea Unsweetened Iced Tea26.0
Barq's Root Beer 23.0
A&W Diet Creme Soda22.0
Slim-Fast Chocolate Flavors 20.0
Snapple Sweet Tea12.0
Lipton Brisk, All Varieties9
Canada Dry Diet Cola 1.2
Diet Rite Cola0
Sprite0
7-Up 0
Mug Root Beer0
Diet Barq's Root Beer0
Sundrop Orange0
Minute Maid Orange0
A&W Root Beer0
Slice0
Sierra Mist0
Fresca0