I just saw you guys riff Stone Cold with Brian Bosworth.
Hysterical!

I'd like to suggest you guys give the same treatment to the 1992 Charlie Sheen movie, Beyond the Law.
Police officer Daniel Saxon (Charlie Sheen) goes undercover in an effort to topple a motorcycle gang whose members deal in illegal weapons and drugs. To prove himself to the gang's leader, a thug called "Blood" (Michael Madsen), Saxon engages in a series of dangerous acts. Though he takes solace in his burgeoning romance with Renee (Linda Fiorentino), a photographer chronicling the gang's lifestyle, Saxon finds the line between police work and criminal behavior increasingly blurry.

www.youtube.com/watch?v=ByJzPwLVR7Y
This is a much better movie than Stone Cold.... I know, I know, so it's more enjoyable as far as the movie getting riffed goes. Plus, Charlie Sheen is a pretty big star. I think you guys could have a lot of fun with this one and I'm sure that it would come out very funny.
Anyone that likes undercover police action movies will like to see this one get riffed.