Azrael's Tear: Search for the Holy Grail

Of course this is very dated now but anyone interested in past adventure games should definitely play it. The atmosphere in its vast underground ancient religious complex is as awe-inspiring as any modern game with superior graphics. The haunting organ music is so good I would leave the game running so I could listen to it. The story is complex and working out which of the characters could be trusted was an extremely interesting challenge.