Halloween Megastore Orlando is open year round with two locations to choose from. OBT & International Drive. Florida's largest selection of adult & children costumes. 1000's of costumes and accessories. When themed parties, birthday parties, events and conventions show's up at random times. We're here when that time happens. Princess, Superhero's, 20's, 50's, 60's, 80's, Police costumes and accessories and lots more....