Buffy The Vampire Slayer: 33 Great Behind The Scenes Shots You Need To See
27. The Gentlemen & Joss
While this isn't a behind the scenes photo as such, it's just too cool not to include and does indeed give an insight into why a particular set of villains were so terrifying.
It shows Joss Whedon in the middle of a Camden Toy/Doug Jones sandwich - two of the brilliant character actors who portrayed the eerie and highly memorable Gentlemen from the acclaimed episode "Hush".