This is by far my favorite out of the Myst series.  Before I knew better, I cheated to get to the ending, looking at walkthroughs.  Unfortunately, it's not like you can 'undo' that memory in your head, and I've forever ruined  the game in my eyes.  The two biggie puzzles in this game involve clues from the whole game you've explored up to that point.  I wish I had taken the time to fully appreciate their solution and not cheat.