NA:
HoC
Brotherhood
Byzantine Guard
Captain America Avengers
Astralis (here and there)
Folkvangr
Gods of War (one person)
House Stark
Knights of KapaWa
Kutt
League of Champions
Lost Legion (occasionally)
Murder Boner
OG
Order of the White Stallion
Remnants
Soldiers of Erzoth
The Coalition?
TooSEXY
Ward of Mithrim
Band of the Hawk
Acre
Defenders of the Viscount (mainly DTV, for obvious reasons)
Dracul / Ravens
Fabulous Killjoys
GFORCE MAFIA
Happy Acid Masks
House Godfrey
Kingsmen
I compiled this list based on banners ive seen within the past week, and sorry if i missed any clans.