Yeah, I've won a couple and lost some where I just think "... the hell???" I have seen a few with costumes in them that seriously blew me away too.
At this point I've learned to not like try to get into such a contest because that gets me geared up about doing well, and there's nothing worse than walking home without a second glance after that*. I just hop by one if I happen to be in Atlas and hear the announcement, which fortunately isn't often as sooner or later I'm bound to explode after losing another one to (I kid you not) another "undead Elvis-looking guy" or something.
*Worst example: big Halloween contest, had set categories for "spookiest," "most beautiful," "most frightening," and another one like that, buuuuut... I'd gone in what was arguably a sort of kitsch or perhaps humor-category costume (that had won other contests!), so I was shut out completely. I wasn't the only one there to feel this way although I didn't bother speaking up like they did. And yes I still think about this because it still annoys!!