How to translate "你给我滚" properly? In a sentence like:

“你给我拿一杯水” You would translate it something like: Get me a glass of water.

How is the "给我" in the sentence “你给我滚” supposed to be translated?

Should it just be "Get lost / Piss off" and just ignore the "给我" part?
Adding to Ciaocibai's answer:

"你给我滚" could be same to "给我滚" and then further reduced to "滚".

In both "你给我滚" and "给我滚", personally, I think the "给我" part is used to make emphasis on strong emotions, such as contempt or strong anger. It will therefore depends on the tune/context to translate it. 

E.g. "给我滚一边去", can be used by a gangster head to someone else who is not important, to show his/her contempt and therefore show his/her superiority in the gang.

Or when a father is really angry at his son who commit a crime, he is furious and shouts out loud "给我滚!"