Here you can find asset stores links that you can use for your games. This site will be updated during project development. If you are looking for assets please read this thread as well.

• Unreal Marketplace
  Its getting bigger and bigger every day.
  Don’t forget about Epic examples! You can use assets from them as well!
• Unity Asset Store
  Currently biggest asset store for game developers. If you are buying 3d assets ask creator if package contains .FBX files. I see that new packages have Unity binary format instead of .FBX files that you can import to 3d program and export to UE4.
• Turbosquid
  Focused on graphics only, but lot of assets!
• GameDevMarket
  Lot’s of 2d assets.
• 3dmodels-textures.com
• http://opengameart.org
• Hum3D
• CG Trader
• CreativeMarket

If you found new Asset Store please let me know!