I adore cosplayers, don't get me wrong, but I think I have a rather harsh, but realistic view of all this.
Am I the only one that gets really annoyed when they see a cosplayer dressing up and they're not 'right' for the character? For example, lets take Sakura Haruno, for example. She's skinny, and has specific outfits. What really annoys me is when an OVERWEIGHT, and obviously so, chooses to dress up as her. When I say obviously, I mean, you can see the bulge of their fat in the 'cosplay'. I don't know why, but when overweight/obese people dress as skinny anime characters it annoys me. Now, I don't have a problem with it all the time, because some over weight people pull the look off well, even if their weight/body types are different. But for the most part, I can't help but cringe every time I walk past an overweight cosplayer dressing as a character that is anywhere from 50-100+ pounds below their weight. What is a little weird for me, is when girls who are maybe, 10 pounds over weight, dress in skimpy clothing as part of a character cosplay. It's weird and I can't help but think 'if only you were toned'.
Oh, and cosplayers who only bother to put on wigs and make up and some cheap excuse for a 'cosplay'. I saw three characters from Naruto this year (if you recognize these people, I'm not trying to be offensive) Sakura, Sasuke and Naruto. Sasuke and Naruto wore white button down shirts and black slacks, saying they were 'Naruto' characters. Done well, it would have been fine, but the way they so obviously just threw it together killed it for me and annoyed me more than anything else. Also, just because you're wearing a 'wig' from Hatsune Miku or some other character doesn't mean you're cosplaying! It just means you're wearing a wig and looking like an IDIOT for saying you're 'cosplaying'.
Men dressing as women characters is odd, but for the most part I'm relatively okay with it. The only time I have a problem is when the men are dressing as skimpy females like Faye Valentine. I saw a Madam Red from Kuroshitsuji, beautifully done by a guy. He was way too tall, but it worked, and was actually kind of appealing to my inner fangirl.
I'm not trying to be offensive here, these are my personal opinions and if I offend anyone, I apologize. I just think this would be an interesting topic to discuss.