I'm making a list of game-ready model shops, if you know another ones please tell me ^^ here's what I've found so far:
(alphabetically sorted)

3dbud.com

(fantasy characters - animals - monters) - <they have just updated new monsters and characters>
3dbud - Real-time 3D models: 3D Characters 3D worlds 3D Demos

3dr*****m
[img]https://3dr*****m/3dm/characters/real-zombies/characters-real-zombies-3d_01.jpg[/img]
(fantasy - scifi characters - animals - monters) <new zombie pack>
3DRT - Buy 3D models: game-ready lowpoly 3d characters, vehicles, levels, game packs

adenfall.com

(game objects)
Adenfall Software

arteria-gaming.com

(game objects)
Arteria3d

cubixstudio.com

(fantasy - scifi characters)
::Cubix Studio::

dexsoft-games.com

(game objects - fantasy - scifi characters) <new cool fantasy characters>
Dexsoft Multimedia, game models, game-ready, low-poly models, textures and music

frogames.net

(game objects - fantasy - scifi characters) <mmorpg character pack>
Game development resources, 3D models & content packs

gamebeep.com

(game objects - fantasy - scifi characters)
GameBeep - Textures, Models, and Sprites for Game Developers

game-stuff.com

(game objects - game levels)
Game-Stuff.com : Buy and sell low-poly 3d model for game (3d game levels, 3d plants, 3d buildings, 3d architects, 3d cars, 3d weapons, 3d characters).