So say for instance I was planing on building a gaming Blog / review site, would I need to go to the publisher of every single games company to get permission to post still images of the game on the site ? as in the end this could become extremely time consuming.
It is always good to ask a specialized lawyer regarding these things. If the pictures are official, promotional pictures, you may. It may also be possible to use them as long as you credit their origin.
If you’re taking screenshots from your computer, well, you still need to specify the origin but this is a different case and I would assume that no, you don’t need to.