I'm a Coke person, though one in a while I have to take a break from it. I've tried some of the Coke variants (except for the new Coke in the black can or whatever. Coke One or Zero or something like that. Just doesn't look appealing to me.)
As for root beer, I like A&W, but my wife prefers Mug. She says it's not as sweet. We both dislike Barq's tremendously.
I was a big Mountain Dew fan as a kid, but not so much anymore. I can drink Dr. Pepper and Pepsi if there is no Coke.