Well, I think I know a bit of how fanboys think, as I've been there. For a period of years you could call me a Nintendo fanboy, but after the Wii launched, I went as far as the ''Nintendo betrayed us''-route, until I redeemed myself. Only after I bought an Xbox 360 and saw that the things offered there weren't all that amazing after all, I went back to Nintendo, and finally got to know my Wii. I now have a PS2 as well, so I quess you could call me an all-rounder now... but of course there's still the Nintendo heart beating in my chest, if you know what I mean.
So I think I would call myself a rational fanboy, if that doesn't take all the meaning away from the word ''fanboy''':P

On topic, I think fanboys don't intent to give their company such a bad image, and it also doesn't have anything to do with them being stupid or something. I think their devotion gradually slipped into irrational blindness. They essentially identify themselves so much with their company, that they become one with their company, seeing competitors only as enemy threats. And then the survival instinct kicks in...
Of course, you have the type of fanboys that take it even further and go out hunting, like our friend Esa-Petteri in this case.

First post! I'll make an introductory topic later, don't feel like it right now.

Do you have any proofs PS fanboys are the worst? They are just as bad as 360 fanboys ( kill, burn destroy Sony ) and wii fanboys ( wii sold better argument FTW!!! )

The only fanboys that really annoy me are Sony fanboys.

I have to agree that Sony fanboys are pretty obnoxious on this forum... but that's only from lurk experience.

Yea, I didn't really mean to say PS fanboys are the worst.  I'll try and retype my op and just leave PS out.  I was trying to imply that it seems that fanboys are getting worse and worse this generation.  The previous generations were pretty bad but it seems to have spread even more lately.  I guess I notice it more due to me browsing various sites more often.

 Last generation, pretty much everyone was pro PS2, there was almost no questioning the power that thing had, game-wise, saleswise, it was overkill.

Now it's like Nintendo vs. Sega in the early '90s: two big, thestosterone'd guys constantly pushing each other and fans getting all worked up over it. The difference now is that this battle is in the back yard of market leader Nintendo, who is used as a shared boxing ball by the both of them. Sega and Nintendo fans didn't have a common enemy until Playstation, and even then that was a different story.

 oh, ok than

I think you need to turn off your computer and go outside. 

Complaining about fanboys on a video game forum is like going to a forest park and complaining about trees.

Just came from a walk outside since I can't jog/run yet (in a week I can, have to wait a little longer since surgery). It is freaking hot outside!!!!! I'll probably go chill on the deck with my Iguana later. You are right complaining about fanboys probably doesn't help much but I was just thinking they are doing more harm than good. People that might be interested in another system might get turned off from that system if they see a bunch of people supporting that system dissing their current system. They might not want to be associated with that "group" of people.

The people most annoyed by fanboys are other fanboys as they're the group most sensitive to fanboy remarks.  If you find yourself getting upset at even small off-the-cuff remarks then you might actually be a fanboy yourself (whether or not you admit it).

As for harm... the people most harmed are fanboys themselves.  By becoming narrow minded, they are specifically locking themselves out of a lot of fun experiences.  Even worse, their own negative perception becomes a self-fulfilling prophecy when they would try games outside of their console/comfort zone.  In fact, fanboys are quite pitiable.