Hehe, It's funny how people here desensitisation and automatically assume it means your kid is a zombie!
I let my boy play stuff like GTA and Halo, I keep a close eye on him, but he's never done anything that would concearn me. Kids learn the difference between a game and reality much quicker than people realise, I seriously doubt that violent games have any lasting negative effects. The positive effects are never brought up. For a start, desensitisation improves your ability to cope with stress, to the point where you don't even get sick as often as more sheltered people. If you play violent video games, it actually makes it easier for you to cope with violent behaviour, it does'nt make you violent, it might mean your more likely to stick up for yourself though.
To tell the truth, the only time I've stopped my son playing a video game was when he was getting really upset at a frustrating part in Spyro on the PSX, I reckon dodgy playability does more harm to your childs frame of mind than any amount of blood and gore.
Van-B
I laugh in the face of fate!