The real litmus test for Mary Sue, I think, boils down to this: if the author's OC (that's original character) trumps the regular characters at every turn, and if the regular characters are either OOC (out of character) to make the OC look good or simply stupid for the same reason, you've got yourself a Mary Sue.
My word, I know people have been calling her a Mary Sue for several seasons, but I didn't realize until I read this just how "Mary Sue" Lana on Smallville really is. Of course that really does make one wonder why the creators of the series won't acknowledge what they've been doing with her all along.
