The Oscars and your senior prom aside, a Halloween party is just about the last place you want to arrive and realize you're wearing the same thing as someone else. If you want to avoid ending up on one side of a "who wore it best" showdown, Frightgeist , from Google Trends , is here to help.Drawing from this year's top 500 costume-related searches, Frightgeist pinpoints which spooky getups are most popular, both nationwide and by region in the U.S. The most-searched Halloween costume in the country right now is Harley Quinn, with the terms "Star Wars," "superhero," "pirate," and "Batman" rounding out the top five. Given the current pop culture atmosphere, none of these are too surprising. The true gems, of course, lie among the local trends.Apparently, many of the good citizens of St. Joseph, MO are taking the simple route and looking for "shark" costume ideas. Meanwhile, we have to wonder what's in the water in the northern states — the top costume search in both Marquette, MI, and Presque Isle, ME, is "clown." Creepy. We just might be steering clear of these (otherwise lovely) states on All Hallows' Eve.To address a national concern: Yes, those dreaded minions were the eighth-most-searched costume, but they were searched the least frequently on the West Coast. If anyone needs us, we'll be in California.