The most memorable (and not for a good reason) was the one my aunt forced on my in elementary school. I was staying with her at the time and she refused to let me wear the cat costume my mom had painstakingly made for me. Instead, she made me a costume she approved of and I had to go to school dressed as the Virgin Mary.
As if things couldn't get worse, I was in public school at the time and some parents & teachers found my costume offensive so I had to sit in the office crying my heart out while all the other kids joined in the parade.
I was too young to understand the ramnifications of wearing a religious costume at a public school.