In the gaming universe, a username is a player's foremost identifier. It is also not something that can be changed repeatedly, and so the. Usernames that you have come up with don't count but any username you have King_Geedorah87 is probably the coolest one i've seen in a while. Gaming - Planet: Member Since: October 15, Posts: Cool usernames people have that are worth. In all honesty, I equally sucked at coming up with cool Gamertags until a call of duty legend taught me the methods she uses to find cool Gamertag ideas.