Even in the once diverse point and click adventure game genre, the Gabriel Knight games were an oddity.
What set them apart was the professionalism of their writing and depth of plot and characters. Jane Jensen, who essentially created GK, took a very mature approach to creating Gabriel and Grace and the result were endearing and interesting protagonists. A lot of work and research went into creating the mysteries they were to resolve - that much is apparent at every turn. Whether it is voodoo in New Orleans, werewolves in Bavaria or templars in France - all of stories in GK were immensely enjoyable and immersive.
Sins of the Fathers may be the oldest of the lot (the other two being the Beast Within and Blood of the Sacred, Blood of the Damned), but it every bit as enjoyable today - simply because that sort of depth seems to be gone out of computer games. For those of you who are just starting to enjoy GK I can only tell you, i wish I was in your place!
Hopefully the other two games in the series will also come to GoG.
Happy hunting Schattenjäger's!
*A word of wisdom:
Save often, Gabe can die!