6.: The Witcher 2
The second game in the series based on Polish author Andrzej Sapkowski takes some very interesting new turns. Taking after the BioWare style of RPGs, Witcher 2 features dynamic dialogs and has an even stronger focus on cinematic presentation than the first game. Also the game features the best action based combat system of any fantasy RPG hands down. When it was released it was a bit rough around the edges, but eventually developer CD Projekt RED released not only a whole number of patches but also an entirely reworked edition, one which the owners of the original game updated to for free.
The Witcher 2 featured a winding storyline across expansive, beautiful levels, interesting takes on established fantasy tropes, and a game world that was well thought through, and riddled with great details, little and big, making it one of the most memorable, most immersive experiences in PC fantasy roleplaying in recent years.