I think I'm the only person on this board who likes the Howling Monkey Cola Energy Drink. It is annoyingly hard to find in Chicago, however. I'll find it one store, and it'll be gone the next week. Other than that, Coke Zero does me well when I want a caffeinated soda.
I used to drink the hell out of Starbucks' "Italian Roast" Iced Coffee, but they've discontinued it to hype their coffee energy drinks... which I'm less excited about. I'll buy the Caribou stuff when it's on sale. The Korean grocery stores carry a cheap iced coffee called, "Let's Be" which isn't too horrible. That one tends to scratch my asian canned iced coffee itch when I get it.
Always remember: "Goatse Loves You"