I drink Dunkin' Donuts coffee because I don't give a damn about the taste and it's cheap. I like the process of drinking coffee... it's a habit of sorts. Not so much an addiction as I have no problems going without coffee.
Coffee (with no milk or sugar) is actually really healthy. It has practically no calories, is high in antioxidants, and feels filling (so you might eat less and thus consume fewer calories). Studies have also linked it to higher longevity and reduced risk of heart disease, liver failure, and Alzheimer's.
It's when you get a grande vanilla latte from Starbucks that you load up on milk, sugar, and caffeine.