I don't know if I would rank it as one of the best I've ever played, but I will admit to enjoying The Witcher. I know... saying it that way is damning it with faint praise.
The interface clunkiness in some of the dialogs makes it less than perfect, but it is intelligently done and not impossible to play if you have a little patience in picking up your skills. Once you accumulate enough cash to start reading books, you can start honing your skill at making potions, oils, and bombs. The game picks up as your alchemy skills pick up. It is open-ended enough that you can pick and choose the order of your quests and explore a lot. Therefore, there is at least SOME illusion of choice in the game even though your choices are a bit limited.
Of course, games of that genre are merely the next generation of adventure books, because in the end, you are just trying to experience the story being told by the authors. It is merely a new medium for experiencing the action, scenery, and intrigue of a well-written story - a medium where you see (and live through) the action rather than read it; where you see the village rather than read its description.
In the end analysis, that is what makes the adventure genre of games fun, and it is the same thing that makes a book fun. If the story is entertaining, then it is going to work its magic on you. If the story is dreck, you'll put the book down and forget about it. Look at the Harry Potter series or the Lord of the Rings - great stories despite their originally being written for a niche audience. Well, if the storyline behind the game is well-written as a piece of fiction first, it has a chance to become a really good game, just as a well-written book has the chance to become a classic. (It's getting late and I'm starting to ramble, so I'll stop here.)
Just a couple of random thoughts from a veteran gamer.