Adventure Gamers has a retro-review up of Quest For Glory IV: Shadows of Darkness, which is my favorite of the series and would be a strong contender for best Sierra game ever, if not for the BUGGINESS. It was difficult to get through it at the time because a key puzzle didn't work right 9 times out of 10. It got impossible shortly after that, because a hardware timing issue would cause it to crash at important points. Also, there was a godawful annoying copy protection routine that required you to quit the game in order to look things up (although I think this was removed in some versions. It's been so long that I can't REMEMBER what the situation is with the CD of the game I'm carrying around).
I loved the story. I loved the rpg/adventure mix that allowed multiple solutions to puzzles, sometimes having to do with objects, sometimes having to do with your skills. I even liked the combat and the ability to set it to strategy mode so I didn't have to DO the combat. :)
I hear there are enough fan patches around that it should be vaguely playable in DOSBox nowadays... I wonder if I can get it to work in Linux and bully certain people into trying it.