Fair point Fourwinds, they are all heavy on the propaganda.
IMOH However partial they are they're all worth a look if your are interested in prehistory, and I'm pretty sure there is a Penguin edition of the Tacitus.
Definitely valuable pieces of history and definitely worth read if you're interested in that kinda thing.
But you are constantly left with the feeling of only having one side of the story. A bit like using the Bible as a character reference for the Devil :-)