So, Stern does not release exact sales figures. In fact, they barely release any sales data, such is their right.
I have always assumed CSI had the lowest run of any Stern (at an estimated 400 units). I heard though that both 24 and BBH had smaller runs. Also, I've heard that if it was not for China then NBA would have been smaller too.
So, which Stern is the rarest?
Modern only (no Catacomb answers). Multiple models of the same game aggregate together: ACDC pro, premium, LE, Luci, and pro LED are all just ACDC for this discussion.