One word: sweetness.
That's right. Coke is better than Pepsi because of sweetness, and I'll explain.
As a soda vs. soda (or pop vs. pop, etc. this link will show you who is right), they are damn close. Coke has a deeper flavor with hints of spices and isn't so much in your face. Pepsi on the other hand does not have that deep symphony of flavors, but when you want something sweet to drink it beats Coke hands down. It is really a matter of taste which you want to drink. (I'll be honest, I am drinking a 20 oz Pepsi as I write.)
However, as far as refreshment goes... who wants sticky sweet when you are sweating like a short order chef using his face salt to flavor the burgers? I don't. I want something that cleans the palate. Bubbles the phlegm away and leaves me with a clear fresh taste in my mouth. Not something that stickily sugar coats my whole mouth, sucking the moisture away. However, most people don't consider this because when you add ice it cuts that sweetness almost in half. So, Coke barely edges Pepsi out for when you want to drink something to quench your man-thirst, but you will only notice it if you are anal retentive (or writing a blog, which probably is not that far off).
Well dipshit, you, most-excellent reader say... where the hell is the soda smackdown or pop punishment? Cooking, I retort.
You cannot cook with Pepsi. It is too damn sweet. Ever heard of Pepsi BBQ sauce? Put that shit on any meat and it becomes trash worthy. What about as a marinade? Coke offers a multitude of flavors with a spicy, earthy tang. Pepsi just gives you sugar. Want an excellent crock pot roast beef? 3-4 lb. beef, a bottle of ketchup, a can of coke, and an onion dip packet are all you need. Try that with Pepsi...and you have meat that comes out of the closet as candy.
I like Pepsi; like I said I am drinking some now. The only thing I dislike about Pepsi are its Britney-esque ads that it seems to think will have you drink it more (of course Coca-Cola Co.'s Sprite commercials aren't much better, arguably worse). But, I will always have a can of coke around.
Rav's Rockin' Cola-Q Sauce
1 can Coke
1 1/2 cups ketchup
1 tbsp Worcestershire sauce
1 tbsp ground hot mustard
2 cloves garlic
1/2 tsp liquid smoke
1/2 tsp white pepper
Put all in the sauce pan. Simmer for an hour (don't even come close to boiling). Cool to room temperature. Eat.