>>720345830 (OP)
Some I remember in no particular order:
>Constructor
The manual was thick as a thesaurus because they printed the whole thing in like 8 different languages.
>Fallout 1 & 2
I remember both as being good and written sort of in character, I think the first one had some recipes for wasteland food.
>Arcanum
Just a really good manual with thorough information about the game, I still have it on my bookshelf
>Starcraft
I remember really enjoying the backstory of the game, don't remember how useful the information in it was though
>Sin
Again, great backstory, the mental image of the main characters burned to a crisp mom waking him up for school sticks with me to this day and I was probably 10 when I read it.