Back when i was in highschool before I played comp tf2 (around late 2007) my friends and I made a clan called Generic Gentlemen or [GG] for short (nothing to do with gangster gang gaming, which had a similar tag at the time).
Myself and like 6 of my friends all named our selves with <name> from <job titlte> using alliteration.
I was [GG] Simon from Sales. Coincidentally I ended up working a sales job for the next 10 years or so of my life. That said it's not a particularily clever or funny name, but it's one of my personal favorites because it brings me back to the days when me and my highschool buds would hop on tf2 (usually on The Drunken Brawl!) and just pubstomp until 3am. So much harder to do that as older adults.