Jerry Baldwin recommends two tablespoons of coffee per six fluid ounces of water:
Semantics aside, on countless occasions I've served our coffee to people for the first time. On first sip, they say, "This is strong." By the third or fourth sip, they say, "This is good." The main surprise, I think, is that most coffee is weak and that's what people are expecting. But as soon as they actually taste the full flavor of fresh, freshly ground, full strength coffee, they have a coffee epiphany.