Half of these are derivative designs, half original. I was designing simply to have enough teams available for my custom leagues, not copyrighted, freely available for non-commercial use.
Conquistadors
Enforcers
Powerhouse
Exterminators
Nemesis
Raging Bull
Tyrants
(Las Vegas) Fallout
Conquerors
Volcanoes
Crusaders
Chaos
Collective
Lincoln Park Pirates
Demolition
Reapers
Lost Boys
Brewers
Avengers
Hurricane
High Voltage
Montreal Underground
Braindead Zombies
Evil League of Evil
Charlotte Uptown
Crusaders
Mavericks
Buffalo Beau Fleuve
Earthquake
Portland Pinot Paradise
Challengers
Basque
Butchers
Jacksonville Blues
New Orleans Penguins
(Gary) Grannies
Tsunami
Nightmare
Sacramento Big Tomato
Henderson Hermit
Richmond Byrd
Vancouver Downpour
New Orleans Penguins Sm
Omaha Sound
Blitzkrieg
(Wichita) Aviation
Orlando Jernigan
Defenders
Salt Lake City Monsters
Riverside Inland Empire
Stockton Delta
Crew
Tulsa Mother Road
Louisville Jockey Club
(Memphis) Cotton Row
Wildfire
(Indianapolis) Naps
Crush
Santo Domingo Calidez Cerveza
Lexington Bluegrass
Long Beach Black Gold
Dominators
Oklahoma City Homesteaders
Knight Raid
San Antonio Alamo
Drifters
Wrecking Crew
Aztecs
Elite
Vancouver Brute Force
Monarchy
Virginia Beach Neptunes
Unstoppable