Witcher 3 is epic in every single way. Today see the release of the first expansion for the title, "Hearts of Stone".
This takes the story to a new level, as Geralt is hunted by Witch hunters, who now turn their attention to Witchers as they've run out of sorceress' to hunt and kill.
Prior to this, if you haven't already, there is a 16GB patch to fix 600 bugs and issues in the base game ready for the expansion. Hearts of Stone itself is 4GB.