Arkham Asylum

If Arkham security was good, it wouldn't be much of a show :)

You're meant to believe that the villains are just that good. These are people that fight Batman on a regular basis after all. Now, there is something to be said for a justice system that doesn't learn from its mistakes and just send these people to unbeatable prisons or even sentence the worst offenders to death, but hey, it's all make believe and how many stories could you tell if Batman only had to stop these people one time and that was it?