Haha. Old thread, but interesting/engaging topic.Disclaimer:
My opinion, if you don't like part of it, criticism and critique... not just criticism! (:
Honestly, I think that cosplayers/booth babes have gotten slightly out of hand. In regards to decency and what is or is not respectable to show off, it honestly comes down to the original art work. I commend someone for pulling off an amazing cosplay, down to the very last detail, but sometimes things just aren't meant to be presented in a convention. There's a fine line between appropriate and inappropriate when it comes to real life versus the internet/media. There should also be that same fine line in regards to conventions; artistically, if your character is very revealing, is that the right time and place to wear that costume? Perhaps if you were going to an adult-themed or 18+ convention, it would be appropriate. Just as they have ratings on games you buy or movie theater tickets, there's kind of an unwritten social norm that overexposure is not appropriate. In all honesty, a lot video game characters/anime characters are beautiful, amazing... but not realistic. If you took their proportions and tried to replicate it on a human body, it would not be the average human image. Ie: super long legs, large chest, skinny waist ... humanly impossible unless you opted for plastic surgery. There are people who believe accuracy is key, but even if your cosplay is down to the last detail, you would never correctly get the proportions (unless the given character is actually drawn to reflect an average human).
A good reflection of this idea I guess would probably be the infamous Dove Commercial (http://www.youtube.com/watch?v=omBfg3UwkYM
So, getting back on topic. It really comes down to our social norms and what we think is acceptable as a society. And, in current society, even if you were trying to depict a character down the pixel - it would be impossible for you to do it 100%. So, why not have some decency to cover it up/modify it slightly so you don't look like you've pulled a character out of the 18+ anime section?
For example: if the girl on the left got a slightly larger bikini (which covered up more of her cleavage) and the one on the right opted for shorts instead of a bikini bottom... I think it would still look amazing and be considered more 'acceptable' for convention purposes.
We don't need to dress like we're attending church, but we do need to consider who else is looking.
And that's just my take on it - apologies if some of it went off topic. (: