The Last House on the Left (1972)
If I Spit on Your Grave is the rape-revenge genre at its worst, than The Last House on the Left might just be its Citizen Kane (1941). The directorial debut of Wes Craven, this is an incredibly important film in the horror canon, and its violence, while not excessive, is purposeful and more effective than most films on this list. This is probably the closest a rape-revenge film will come to respectability.