Personally, I think that the effects of playing video games are always going to depend on a lot more factors than just the game itself. Mostly, it comes down to the big headlines like depressed people who happen to be gamers snapping a few mental links and going crazy in public. The key question then becomes what else is going on in that person's life not what game did they play.
On a different side, I can't play first person shooter games, they make me sick to my stomach after about 20 minutes. I'm not sure what's up with that, but all that means is that I have to choose a different sort of game. I tend to go more role-playing as a result.