This year's entries were no exception.
Contestants often spend weeks or even months on their costumes. The pop culture references were current (like the shredded Banksy artwork), throwback (like Rosey the robot from the Jetsons) and everywhere in between.
Some weren't references at all: One man said his funky disco-themed costume came to him in a dream.
Check out some of the most impressive and inventive costumes in the gallery below and videos above.
The Live with Kelly and Ryan Halloween "Reboooot" special included plenty of throwback costumes for the hosts as well.
Check out highlights on their YouTube channel.