I snuck into Defcon 2015 with a fake badge!
At the Defcon 2015 convention, the "Tamper Evident" village had a fake-badge making contest. The 2015 defcon badge was an actual vinyl record that you wore around your neck! Someone else won the contest with a badge made from plastic, and a label that he printed out, but I was more proud of my entry - I just drew the record label by hand with a pen on a cardboard disk. There's a redshirt (volunteer) at the front of the convention who looks at everyone coming in and points to their badge and says "Badge" outloud.
I walk in, cardboard circle on my lanyard.
"badge! badge! badge! badge!"
I get closer to the redshirt. He points at me...
I was so proud
I walked in and out of defcon all day with this badge! They finally noticed when I went up to a group of redshirts and asked a question and stood there for a while, but at that point I was just getting cocky.