Almost every FNaF map uses CSS textures for the floors and walls.
Functional office doors, working lights, and a spooky atmosphere. Direct Link: Freddy Fazbear's Pizza - Steam Workshop fnaf+1+map+gmod+link
If you want the "OG" experience that many early GMod YouTubers used, this is likely it. It focuses on atmosphere and accuracy. Almost every FNaF map uses CSS textures for