Forename
Ally
Azar
Baloki
Bert
Big D
Blues Agent
boris no no
Breine
Brian The Pink Shark
Caraliz
Chemical
Chloe.
Chris
Craig
Daryl
Del Murder
Doofhull
Doomgaze
edczxcvbnm
Endless
erikramza
Faris
fire_of_avalon
Flying Mullet
Freya
I Took the Red Pill
I'm my own MILF
Jack
Jebus
Jessweeeeding
JojeeJowy
Leeza
m4tt
MecaKane
Mellisaur
Mikztsu
Mittopotahis
Momiji
-N-
Nait
Nephemera
o_O
Ouch!
Primus Inter Pares
Raebus
Raistlin
Rantzien
Rocket Edge
RSL
rubah
Russielloyd
Rye
Sakura Yume
SammieBabe
Samuraid
ScottNUMBERS
Shaun
Shauna
Shawtiie
ShlupQuack
Shoeberto
Skye-chan
Spiffing Cheese
Strider
Sugpo
The Abominatrix
The Summoner of Leviathan
theundeadhero
Winged Sorceress
Zeldy
Forename & Surname
Ashi
Calliope
Chickencha
Chronos
Cid
Citizen Bleys
DK
Drift
Etienne
God
GokukidNUMBERS
Jess
Jewels
Kalenisis
Levian
Linus
Loony_JosH
Miriamel
Miriel
ms_devli
MsTiffie
Mum
Psychotic
Raven1073
Rinoabella
Scottie
Shorty
smittenkitten
The Man
Tweety_ch1ck
Zell's Fists of Fury
So basically at least 100. Can't be bothered looking going through names for longer.
EDIT: I'm not sure which are common knowledge and which aren't so you're gonna have to trust me as to the fact that I know their names.
As for "cheating", I will at the least admit that I did a quick search through the memberlist of people with over 1000 posts, but it would be a little
too time consuming to try to remember all of the usernames off the top of my head!