I have no idea what sort of name to give that type of character-fail. I do think it needs to be descriptive, like SitLR, so that the issue is right there in the name. I strongly believe it needs to be genderless. And it'd be nice if it showed that there was some personal opinion going on there (one person's character-fail is another person's darling, after all). So maybe something that suggests the emotional aspect of the failure

Total agreement here - especially on the personal opinion factor. Really I wish fans were better about saying, "I think that char is a Mary Sue" or "That char comes across like a Mary Sue to me" anyway - because heck, any opinion about a fandom is just that, an opinion, and I wish fans in general were more respectful of opposing opinions - but if that was implicit in the phrase, so much the better!

(If you come up with anything, let me know - I'm serious, I want a replacement word!)