The first Witcher (W1) game released back in 2007 is most likely one of my favorite RPGs of all time due to its complex, gripping story-line and living world. The game is great at pulling you in and making you feel attached to each choice and action, but not without flaws. The combat system was somewhat heavy and the engine was a bit sluggish. Regardless of its flaws, it was still one of the best RPG games I've ever played.
The W2 improves upon the original game in just about every possible way. Interface, graphics, combat, etc. and have all been modified for the better. The graphics engine in the W2 is amazing. In my opinion, it is one of the best looking RPGs out there today. With a high end gaming pc, you will be blown away by the detail in the atmosphere, the forests / landscapes look great. Basically, graphics aren't the most important aspect of a video game, but they can help bring a feeling of captivation and W2 does just that.
The Polish developer and publisher CD Projekt RED recently revealed that the third and final chapter of Geralt's story, Witcher 3 Wild Hunt, is currently in development. The W3 is set in an open world bigger than any other games in the series with anticipation of 100 hours gameplay, and will utilize the REDengine 3 game engine.
The Witcher 3 Wild Hunt is due for release sometime in 2014 for PS4 and PC.