Translating is always a matter of tradeoffs. Part of the task of a translator is to make the translation as close to the original as possible. On the other hand, if a work is a beautiful poem or stylistically skilful novel or essay in the original language, in order to convey an impression of literary merit, one must create an equally good literary work in English, something that may mean being less literal, Another problem is that culturally specific humour, idiomatic phrases, and references don't always translate; for example, the phrase "c'est de rien" (it is nothing) is best conveyed by the English "no problem" or the Latin American idiom "better than eating bats" might be best expressed in English as "better than being poked in the eye with a sharp stick".
In order to find a good translation of a specific work, when multiple translations are available, you should search the MLA bibliography and Expanded Academic Index on your university library e-resources for reviews which evaluate the quality of the translation. To find a complete list of available translations of a given work, search WorldCat by author name.