I like outfits that combine good face painting with articles that you can find ops round the house. Some of my recent ones are: Fantastic Mr. Fox (brown leggings, shirt, waistcoat, fox face paint), Statue of Liberty or Weeping Angel (grey face paint and an artistically arranged grey sheet, plus egg box insides for the Statue of Liberty headdress), Day of the Dead (skull face, white blouse, black skirt).
Some of the baddies from fairy tales can make good dress up options or the baddie from a kids favorite cartoon or film. The ugly sisters from Cinderella, Cruella De-Ville from 101 Dalmatians, Ursula from A Little Mermaid, the Green Goblin from Spider-Man, or Captain Hook from Peter Pan. Or how about with all these ghosts and witches about, you come dressed to battle evil so think super heroes, Lara Croft, the Blue Fairy, Snow White.
I like to dress up in happy costumes like a fairy, a French maid, a nurse, perhaps tinker bell or a fairy godmother. Perhaps dressing up as a naughty school kid. I had friends who saw a man dressed up as a poker machine, it was so unique he won the prize of the night!
My daughter recently dressed up as an 'un-dead' bride for Doctor Scary's Maze at the Perth Royal Show. Basically, she simply dressed up in an old bridal outfit, but with 'monster' makeup....face painted white, black lipstick, lots of dramatic black eye makeup and fake blood. She showed me some photos...the outfit looked seriously creepy. Perfect for a Halloween outfit with a difference.
A lot of people dress-up in non-Halloween gear these days, such as characters from their favourite TV programme. Star Trek costumes are a prime example. If you want to be more traditional though, a good alternative costume is The Headless Horseman as it is still very much in the Halloween spirit, yet isn't used a lot as a costume. All you need is a cape that will fit over your head, a pumpkin/jack o lantern to hold balance on top, and a hobby horse.