I'm completely unaffected by caffeine... I'm pretty sure coffee flows through my veins too >.>
Luckily not an addiction though, decided to see what'd happen if I went 3 months with no 'obvious' caffeine intake (coffee, tea, energy drinks, etc) (not counting things like coke or chocolate, though I did try to limit thoe too) and as much as I WANTED coffee I never felt what I imagine a craving would be and I felt fine the whole way through...
Iced Coffee is easily my favorite drink, and I drink my hot coffees black, 3 sugars and with enough coffee grounds to kill a child >.>