The Elder Scrolls Construction set is fun to play with. I haven't actually done anything with it, but I've found some interesting things.
I went through all of Martin's dialog, and all of Jauffre's dialog, and I read the script notes. Most of it is only interesting if you're as obsessive about character motivation as I am, but some of it is just funny. Like how all of Martin's early notes include the word "bitter."
I looked through all the scripts for the main quest. Again, only really interesting to me, because I'm compulsive, but there's some entertaining stuff. Like "Mankar has left the building." And "CloudRulerMartinStudyClutterMaster.enable." Finding these is left as an exercise for the reader.