Halloween costume

Why is it that it is nearly impossible to find a cute, non-dumpy Halloween costume that doesn't make a girl looks slutty? I don't understand what it is with Halloween that makes girls think they've got a pass on that night to dress (and often act) as slutty as possible.
With Halloween quickly approaching (as well as our cruise which leaves on Halloween), I find myself frustrated that the only costumes I can find are "sexy"(insert profession here)s. Or, the costume is of a superhero which basically means spandex. I don't look good in spandex (who does really?) And let me tell you nobody needs to see that!

The other frustrating aspect (which is slowly becoming a non issue as I can't find anything!) is that Matt and I wanted to coordinate our costumes. All the couple's costume ideas are weird, creepy or dumb. Ball and chain? No thanks. Ketchup and Mustard? What the heck? Marc Anthony and Cleopatra? Boring! It's hard to find a couple that involves both of us dressing up. Matt had the idea of Dr. Horrible, but Penny is just in regular clothes. Perhaps I could cross-dress and be Dr. Who...

Any way, I write this in the hopes that anybody has a good idea for us. It would be great if the costumes were coordinated or related, but at this point I don't much care if it isn't. So far the top runners in our minds are:

1. Wolverine and Rogue - I know they weren't a couple but they're good friends. Plus, Matt can really pull off the beard and hair. It does however require an incredible amount of spandex on my part.
2. Dr. Who (Danid Tennant style) and his companion - I would love to do this one, but again, I would just be in regular clothes. Boring!
3. Christine Daae and The Phantom - I love this musical more than life! However, Matt's costume would be stifling, what with the shirt and vest and pants and cloak and mask...
4. King Leonidas and his Queen - Matt would not be naked at all, but again, he can pull of the beard. 

So, there you have it. Any ideas would be greatly appreciated!