"The translations of Zarathustra dissent according to the sentiments of the translators for the English language. For instance, the Thomas Common translation, widely available, favors a more biblical approach. As a partial consequence, that is, these claims are not limited to its biblical, archaic features, some have claimed it is inaccurate and/or possesses Nazi distortions by Nietzsche's sister. By contrast, the current and much more critical translations, titled Thus Spoke Zarathustra, separately by R.J. Hollingdale and Walter Kaufmann, who also contested the inaccuracies of Common's translation, are considered, in various circles, to convey more accurately the minutiae of the German text than Thus Spake Zarathustra. In these translations the work is rendered in a far more familiar, less archaic, style of language."
From wikipedia. Which one you reading?