I think every group has its offenders.
In general, Xbox fanboys tend to attack the ps3 quite harshly, posting lots of news stories that make ps3 look like a sinking ship, which we all know it isn't.
But PS3 fans would overhype tetris as the most visually impressive game if it was a ps3 exclusive. like every exclusive is the greatest game up to that point. I have seen 100s of animated gif explosions for killzone 2 on this forum but have yet to read a good preview of the game that someone postd here.
I'm not touching wii fans with a 10 foot pole. tres tres will kill me if i say anything bad...