I might as well cut & paste my list of games and remove some adventure games, Morrowind and a couple of other ones. I don't usually finish games, because a new interesting one pops up and the other doesn't have enough 'power' to still attract me. Couple of examples:
Arx Fatalis - I got stuck on it this summer, I was really looking forward to finish it but now I have other games to play, and I put the box on my desk just to 'remember'. In Memoriam, maybe (which I actually finished)
Gabriel Knight 3 - I had to put this, I installed it like 4/5 times and never finished it. But now I'm working hard to do it, I HAVE to finish it
Heart of Darkness - man, this sucks! This too has gone through the installation process a zillion times and I've never finished it.
UFO Aftermath - I guess I just played it too much, it didn't deserve that much attention