At this point I'm just one of the choir, but that's OK - this game is terrific. It was great back when it first came out, and it still has the goods. Playing the original Gabriel Knight in the modern day does require a small adjustment to headspace - big crunchy pixels! and sound that is occasionally balky - but the story is satisfying, the gameplay is good, and the voice acting is simply stellar.
I played this game when it first came out, back when the whole world was made of big crunchy pixels and balky sound, and enjoyed it a great deal (though I didn't finish, and got stuck a lot). I wasn't sure if it would still be fun, these 20 years later - and I'm glad to say that it really is. Once you get used to the blunt tools of the day, the great game is still intact and ready to take you on a ride.
I could say more, but it's all already been said, and a hundred times over. This is a joy of a game, from a time when developers were boldly stepping out to try new things. It feels fresh and alive, and I just finished it - I'm ready to recommend it heartily.