There was an actual, legit, non-XXX arcade in Yuma, AZ that had a secret entrance in the back that led to an actual XXX arcade (and what seemed to be a whole lot more, nudge nudge).
The XXX arcades in Honolulu, HI used to have arcade games and pinball in them. They specialized in having at least one of those Qix-type games where you uncovered a picture of a nude woman. Kinda quaint, actually.