The original post is a complete mess!
The facts:
1. We use the OFLC ratings, because we adapted our movie ratings to suit video games.
2. We use a government-run ratings board simply because it keeps us from having a bunch of angry, moronic parents claiming that industry self-regulation doesn't work.
3. Manhunt is the only game worth playing that has been banned here (the rating was reviewed six months after release due to a media frenzy and the game was banned, but sales of the game were pretty much dead and it was already in the bargain bins).
4. No GTA game has actually suffered for the minor content changes that were made (they only took out the ability to sleep with hookers, the game isn't broken because of that).