9. Lock Up
One of Sly's most egregious flops, but also one of his most forgettable, Lock Up sees Stallone play Frank Leone, a man who winds up in a maximum security prison to see out the last days of his sentence, presided over by the sadistic Warden Drumgoole (Donald Sutherland), who wants to ensure it becomes a living Hell for Frank. While the notion of a prison movie seems to fit the burly actor like a glove, there's just nothing fun or thrilling about it (hence it being perhaps his most unmemorable film to date), and the film takes itself
far too seriously given that it's clearly ripe as a bit of B-movie pulp. Stallone mumbles his way through it without a seeming care in the world, and even a high-class actor like Sutherland doesn't fare much better. Terrible.