Sadly, you are all guilty of the same accusations you are throwing at your own opponents: of not having perspective.
Video games DO cause increased aggression and violence. This is an indisputable fact, backed by numerous case studies and experiments (and yes, there ARE peer reviewed experiments, done on gamers of ALL ages, and not just those who play violent video games; to argue that you cannot think of a viable experiment is an argument from ignorance or lack of imagination).
Due to this psychological and experimentally verified fact, two camps have developed: denialists and destructionists. This forum, obviously with a video game bias (which isn't necessarily bad, don't take that as judgment, I was playing Left 4 Dead before I saw this), is a denialist camp. You deny the hard data even exists. The other camp is the soccer moms, that want to destroy video games, or render them castrated, to protect the children.
The problem is, you are both missing the OTHER side of the data. Video games cause LESS violence than PHYSICAL sports, a notable example being football. Football causes the most long term effects on aggression, BY FAR. Even BOARD GAMES cause an increase in aggression, so it is absolutely ridiculous to deny video games, with fancy graphics and increased gore, wouldn't cause increased aggression and tendency towards violence, when a simple board game like Monopoly does (and I know all of you that have played Monopoly recognize this). On the other hand, it is just as ridiculous to try and regulate or destroy a field which causes FAR less violence than something as popular as football. If the soccer moms REALLY wanted to reduce violence, they'd stop taking their kids to soccer.
All this being said, both camps use the same flawed arguments. A single example, either way, does not imply a universal example: just because the members of this forum do not feel inclined towards violence, does not mean a large percentage are not. And vise versa, of course! Just because some people fly off the handle does not mean EVERYONE will.
The point to take away from this admittedly long post (the original deconstructed most of the arguments people have posted here, but I felt it would be unfair, since apparently no one has actually done psychological research as I have) is that video games cause aggression and violence, but so does a lot of other things, and the measurements already in place are by and far sufficient. This is the opinion of me, and the vast majority of the medical community, and if anyone in either camp actually cared to look at the research and recommendations of experts, we probably wouldn't even care about this non-issue right now.
tl;dr: shut the hell up about shit you have no real knowledge about.