One of my favorite campaigns of all time is a set of PSA's put out by the Montana Meth Project.
"The Montana Meth Project is a large-scale exercise in prevention, aimed at significantly reducing Meth use in Montana. The integrated program consists of an ongoing, research-based marketing campaign—supported by community outreach and public policy initiatives—that realistically and graphically communicate the risks of methamphetamine to the youth of Montana."
One of my favorite examples:
Monanta Meth Project's website.