Just to be THAT guy, I would like to point out that I went to High School with McGraken and I happened to be the guy that looked over his shoulder and noticed the default username he was typing in to log in to see his grades was actually a super badass name and that he should use it. So I guess that I'll use this as a segway to add in my nickname story.
I have never been too creative, so I have become more of a copier, which is kind of lame for a nickname, but oh well. As such, I have gone through tons of names copying what I think to be the coolest at the time. Beau was a cool elf name from DnD a while ago, AllThatRemained for COD taken from one of my favorite bands (got razzed by my buddies that all that remained was my gun, because I was always dead ), to a couple of different names in WoW (a few from that trusty randomizer I know you all love) to Emoshock as a Shaman name that I stole from someone when I switched servers and then BigFatJiji as a LoL player. The only name I really ever made was my League of Legends name OOBERNERD, which I was rather proud of. I like the ALL CAPS IN YOUR FACE as well as the NERD about to pawn you, and the uniqueness because I spelled uber incorrectly. Currently, for MMO characters I just really like to steal my favorite anime names for my characters like Kirigaya from Sword Art Online as a warrior, and Okarin from Steins Gate as my Mad Scientist Engineer and such. So I guess as a true nickname mine would be OOBERNERD, but I have come to really like Okarin as well, because of how it reminds me of Mayushii and how damn cute she is, "Okariiin, tuturuu!"