I drink 2 cups of coffee and usually 1 soft drink per day. At that level, I sleep well, don't get the jitters, and I can still enjoy coffee. I'm not a big-time coffee snob, but I do make my own with locally roasted beans when I'm at home or in the office. Its more about the freshness for me, rather than whether the bean is from Kona or Sumatra or Columbia. Our cafeteria coffee is un-drinkable, but most restaurants do OK in my view.
I have been as high as 4-5 cups of coffee and 2-3 soft drinks, and that was noticeably unhealthy. Blood pressure was up, sleep was so-so, and I felt wired all the time. I've also tried going caffeine-free, and to be honest I didn't feel any better than I do at my current level (and yes, I tried it long enough to fully adapt). Caffeine itself is harmless in small doses, and coffee (like tea) actually has beneficial antioxidants and trace elements.
Soda- no benefit at all, just straight bad for you no matter how you look at it. But I like it so I allow myself one a day. Dublin Dr. Pepper with no corn syrup. ;-)