I like Coke more than Pepsi, as well as Sprite more than 7-up, so Coke wins IMO.
I just realized today that Dr. Pepper is Coke marketed as well, making Coke even more awesome.
However I prefer Mug root-beer (a Pepsi product) to Barq's (the Coke product).
Off Topic:
I have noticed that whenever I'm at a restaurant and I don't know what brand sponsors them, I always guess the wrong one. If I ask for a Coke, they always say "Is Pepsi okay?" and if I guess Pepsi then they always ask if Coke is okay. It's frustrating.