Come October 31, kids all over the world dress up in fancy costumes and take to the streets for the age-old tradition of trick or treating. However, kids are no longer the only ones allowed to have fun during Halloween. Grown-ups have learned to love this holiday as well, which they celebrate with grand costume parties. There is usually a “Best Costume” prize awarded at these parties so naturally, you would want to stand out from the rest of the dinner guests by having some unique adult Halloween costume ideas. This is not really a problem for most people as there is no shortage of ideas to select from, ranging from the typical witch and vampire to more contemporary costumes like celebrity look-alikes.