One of The Witcher 3's greatest assets is its open world.
The story grabs you from the start and doesn't let you go, with every character, subplot, and detail making you think and reflect on the world you are in. It's a tale full of grey areas and amorality: there's no simple good and evil, only people surviving and trying to do the best they can in difficult circumstances.
The plot of The Witcher 3 supersedes those of the greatest RPGs of the last generation, Skyrim, Dragon Age and Bioware's Mass Effect series.