In reply to Zorbel's post, which I didn't bother quoting since it was large:
Oh but I prefer sticking to witty remarks. You see, if I don't actually give suggestions than people can villainize me in their minds and it makes it easier to take my sarcasm and arrogance since they can believe that I'm just a jerk who picks on people with no reason but doesn't even have anything constructive to say... This way I get the satisfaction of poking holes in people's ideas, and they get the satisfaction of ignoring what I have to say with a healthy amount of self-righteous indignation. If I started actually giving ideas, people would have to pay attention, and it would be a huge blow to their egos. I wouldn't be so selfish as to put people through that humiliation, just so I can imagine the exquisite looks of frustration on their face as they realize that not only am I a jerk, but I'm right... So really, I'm just looking out for everyone else.

I like it... punish godmodding with godmodding... Nice.
Is there another way? ... besides UtM's way of sacrificing your character in permadeath and guilt tripping them? 
Well, that is always fun. Frankly, there are lots of ways to ignore bad RP. Different people have different ways of doing it, and that's fine with me if it works for the situation. Personally, though... I tend to take a passive approach. By this, I mean that while I'm comfortable ignoring a godmodder, or RPing away his actions into insignificance, I'm not will to become a bad RPer by super-imposing an action upon him. It's the principle of the thing... If he's annoying me by super-imposing my actions or his worth upon my RP, then I'm not going to do the same back to him. I'll let it slide, RP around it, RP his actions into relative insignifance, raise an eyebrow at him and treat him as though he's mentally deluded, or even, in desperate times, ignore certain things that he's said(obviously I will have /telled him that his behavior isn't appropriate, but of course that is not guaranteed to work) and move on as though they never took place. I have more patience than most due to life circumstances, and am not afflicted by a short temper, so I have never found it necessary to /ignore someone when I can just ignore them.
So to recap... I'm not saying that the ideas previously mentioned in this thread are bad... I'm saying you have to be smart about it and think on your feet... What may work in one situation may not in another... what may be necessary in one situation may be an overreaction in another... what may seem fine in one situation may be ethically questionable in another... I'm not going to make your decisions for you, but don't get into the habit of treating every person with a single remedy. There is not a single remedy for bad RP.
Look what you've done now, Zorbels... People might actually have to stop and think about what I have to say... I hope you're happy!