greatmarx for my ROBLOX account. I was a huge fan of the Kirby series and my favorite character was Marx. Back when I made my account, ROBLOX had some weird ass thing where I HAD to put an adjective in my username, so I just did "greatmarx" without any capitalization because I was 8 years old.
Even worse was my first Xbox Live name:
Give me a break I was about 9 or 10 years old and Montage Parodies were the cool kid thing so I thought "Swag" was the pinnacle of comedy.
I was named hhhhh222 on minecraft the first time I played. My mom though you could access one's account with just your name. That remained my name untill I figured out how to change my name and explain it to my dinosaur of a mom.