I think sueing the entire state + police officers who arrested them and everyone else involved. I know 20+ years of being in jail won't give them back their lives but at least they can be rich =D.
I especially feel bad for all involved. I did a paper about the West Memphis Three back in Jr. College. I got everyone in my class to donate to their case including my teacher. It's sad that they locked away them boys, who of which is mentally handicapped for that long.