15. S&M Lego
The laughs and respect this guy got probably more than made up for his inability to hold a beer for the entire length of time he wore this costume, as well as the number of children whose childhoods were destroyed with just one glance.
14. Ramona Flowers
There's nothing about this costume that doesn't work, except perhaps any guy's opening line when they tried to take her home. More impressive than the homemade hammer is the fact a khaki dress actually looks good.
13. Cool Runnings
This costume is almost as great as visualizing the group drawing short straws to decide who was going to carry the toboggan around all night when they weren't posing for photos. That and how long they decided to keep the undoubtedly terrible Jamaican accents up for.
12. Beaker and Dr. Bunsen
Going even a little wrong with a Muppet mask can mean going out at Halloween as a weirdly-colored paper monster. This is a perfect recreation of two beloved Muppets, right down to Beaker's trademark iPhone 4.
11. Mario Kart
The biggest issue with group costumes is staying together enough for people to "get" it. These smarties have overcome this: the reveal is all the more impressive when people notice every single Mario Kart character is running around at the party.