What size Halloween costume should I get?

My girlfriend is trying to remember the name of a halloween movie or tv show where kids stop believing in halloween and a witch is losing her power because of it, or something along those lines. She can't remember much else, she hasn't seen it in years but really wants to see it again and I'm...

Hello I am wanting to find a pop star costume that is rather modest (long skirt or pants) and preferably including the headset thingy. If there's any ideas of where I can look I would appreciate it. Thanks!

I am trying to think of costumes for me and my friend to wear for Halloween. We are both girls, brunettes, white, in our 20s. The more imaginative the better... We've already considered nurses, fairys, princesses, showgirls, flappers, pink ladies etc... Scary / horror would be cool,...

I have to do a presentation to my chemistry class on the enzyme Trypsin. I need some help finding an idea for a prop or costume that I could wear. Does anyone have any ideas?

What should I be? I was thinking maybe a flapper or Daphine for Scooby-Doo, but I'm not exactly sure