I will have to agree about Sorority babes in the Slimeball Bowl-a-Rama having a great spanking scene (Brinke Stevens and ?) and also being one of the all time worst movies ever made.

John Wayne is of course King of the mainstream spankers ... or should that be Duke? Everyone remembers Maureen O'Hara's spanking but seem to forget the lovely Srefanie Powers getting her bottom warmed and again by a coal shovel or ash shovel

Another favorite of mine is Nora (Myrna Loy) getting her spanking by husband Nick (William Powell) in The Thin Man Goes Home.