Save for the northwestern German tribes of the Anglo-Frisian and Saxon type, which appear to be genuinely Germanic, most other western German tribes were of Celtic descend. Before the imperial days of Rome, Celts were stronger than Germanics. They were more civilised if you disregard their cruel human sacrificing which happened on a frequent basis. That is why Celts were said to possess an extensive religion which they took very serious, through the caste of druids who let the blood flow. Still they had villages, cities, forts and respected individual privacy. Germanics lived in a commune, meaning that there were houses but they were common good. This means that you are obliged to receive visitors, give them food and shelter for as long as they want, and you can do the same to others. Although they also practiced human sacrifice on a frequent basis, their religion was simpler and fate played a great role. They practiced a form of divination practically identical with the I Ching.
The closest description of a Germanic tribes I could find that resembles the modern German character were the Chatti from the region Hesse. Citing Tacitus' Germania:
>[The Chatti's] settlements begin at the Hercynian forest, where the country is not so open and marshy as in the other cantons into which Germany stretches. They are found where there are hills, and with them grow less frequent, for the Hercynian forest keeps close till it has seen the last of its native Chatti.