As I recall, one chute failed to deploy on Apollo 15 resulting in a bumpier splashdown.
Also, Mercury had an additional egress point in which the astronaut had to climb-out the top of the capsule.
I strongly recommend watching the Discovery channel documentaries MoonMachines and especially the ones about the Apollo capsule parachutes. According to the guy who designed the parachutes, they were so tightly packed that they had the density of maple wood! Another section that I really liked was about the Launch Escape System (LES) which is designed to pull the capsule in case the Saturn rocket goes kaput. This actually failed during testing (the rocket came apart) and caused LES to fire which was a verification of an actual failure.