This is an attempt to classify the various ranges available (and no longer available) with their closest equivalents to the Games Workshop ranges where possible.
2nd/3rd Edition Style Miniatures
Games Workshop - Chaos Dwarfs 2nd&3rd Edition Warhammer [OOP]
Games Workshop - Hobgoblins 2nd&3rd Edition Warhammer [OOP]
Macrocosm/Warblade Miniatures (Metal models available)
Oldschool Miniatures (Metal models available)
Small range 3D sculptors (STLs available)
Ellie Valkyrie (small range Chaos Dwarfs)
Knightmare Miniatures (small range Chaos Dwarfs)
Mordin (small range Chaos Dwarf war machines)
Paimon Miniatures (small range Chaos Dwarfs)
Warploque Miniatures (small range Chaos Dwarfs)
4th/5th Edition Style Miniatures
Games Workshop - Chaos Dwarfs and Hobgoblins of 4th&5th Edition Warhammer [OOP]
Brawniac Miniatures (STLs available)
Fabelzel’s Models and Remixes (STLs available)
Tom Wiggins (STLs available)
Zonk miniatures [OOP]
1st Forge (small range of Hobgoblins)
Custephica (small range Chaos Dwarfs)
Max152 (small range)
Maxmini (small range Hobgoblins)
Ystlund (small range Hobgoblins)
Legion of Azgorh Style Miniatures
Games Workshop - Chaos Dwarfs (Legion of Azgorh) 7th&8th Edition Warhammer [OOP]
MeshyMesh (STLs available)
Mean Man Industries (STLs available)
White Angel Miniatures (STLs available)
Norba Miniatures
Tortuga Bay Studio
Small range 3D sculptors (STLs available)
Empire Miniatures (small range Chaos Dwarfs)
GrimmGitz (small range Chaos Dwarfs)
Mix of Styles or Alternative Style Miniatures
Games Workshop - Age of Sigmar (plastic kits)
Games Workshop - Blood Bowl (Some OOP and plastic kits)
Highlands Miniatures (STLs available)
Lost Kingdom Miniatures (STLs available)
MOMminiatures (STLs available)
Titan Forge Miniatures (STLs available)
Mantic Miniatures (plastic kits, some STLs)
Scibor Miniatures (metal/resin casts)
Russian Alternative Miniatures [OOP]
Small range 3D sculptors (STLs available)
Cornixt (small range of Chaos Dwarfs and war machines)
Forlorn Hope Games (4th ed style Hobgoblins, 3rd ed style Chaos Dwarfs
Morgenstern Printing (small range Chaos Dwarf characters)
Onmioji/Stanislav Kuznetsov (small range Chaos Dwarfs)
Sneakygitz (small range war machines)
Svennh (small range war machines)
Titan Wargames (small range Chaos Dwarfs)
Wetox (small range Chaos Dwarfs)
Yedharo Models (small range Bull Centaurs)