Don't remember seeing this before, soooo (this may be a long list, and I most probably have excluded some people accidentally, sorry!)

Strato/Infinite Spaz
AvK
Velkasha
Magoo
Trafty
gummi
Iam Canadian
Darker
Shibby
anaiyu
Urjazz
Spotty
Boarder
TurtleSlayer
Faw & Rad (except when Radium drew lewd imagery of me, and didn't listen to mine or sal's request to turn my feet into apples )
Pyromanus
blur
Kirby SSb/Cosmo (the guy who made all the test maps you all still play even now )
Gr33n Pl4nt
Ducky
Nimrod
Monolith
Derby
White Rabbit
Cell
Spaztic
Dersproedel
r3p
Ninja
Black Ninja
Red Ninja
iCeD
Fireclaw
Xion
Chavrash
Dalspots
Yaxo
James aka Jman FoR
Tman
Darkshadow
danyjel
danX
mErlyn
supreme overlord of j2o Frank Quist
Iri
Jizor
Link
Blade
4I Falcon
Satan
P4ul
mezz!
fod
batty buddy
Spl@sh
bunnyelmer
veggieman
exodus
cpp/Overlord
scizor CT
slayo
maverick
Cobra/ninjapixie
chippie
Aegis
evilmonkey
sasik
toxic bunny
thunder
Tublear
Kakashi
stripe
Shorty
Unhit
Supersaiyan
I've been hard to stay in touch with and been mia from the game for a long while, so unfortunately haven't had contact with some of these guys for ages. Some people who would otherwise be on this list (Bobby, Enigma, mdnchmr/Chimaera, Salamander, Violet, mike, snooze, lark, fs, Ae/adam/vowels etc) I've seen around recently or talk to so they don't count ;P

edit #1: already added some names : #
edit #2: spaztic was so cool i mentioned him twice