Unity3D Assets

Advanced Terrain Shaders – unitypackage
http://forum.unity3d.com/viewtopic.php?t=45290

Snowify – generates snow-meshes for your assets, automatically unwrapped and textured
https://www.assetstore.unity3d.com/en/#!/content/6343

UniStorm
https://www.assetstore.unity3d.com/en/#!/content/2714
https://www.assetstore.unity3d.com/en/#!/content/3927

DriftingClouds – MovingClouds.unitypackage
http://forum.unity3d.com/viewtopic.php?t=45290&postdays=0&postorder=asc&start=15

Animated Human Marine Model Pack
http://www.stefanmensen.nl/cheapmodels/Characters.html

Frogames ProtoPack – rapid prototyping for Unity Games
http://www.frogames.net/?r=3&data=iu3d-toolslist

Arteria 3D Content Packs
http://www.arteria3d.com

Unity Prefabs
http://www.unityprefabs.com

Indie Game Market
http://www.indiegamemarket.com

Unity3D Marketplace
http://unity3dmall.com

Unity3dx
http://www.unity3dx.com

UnityMagic.com – Assets and Packages
http://www.unity-3d.com

Skyboxes and Panoramas
http://forum.unity3d.com/viewtopic.php?t=59965
http://forum.unity3d.com/viewtopic.php?t=63407

Dungeon Construction Kit
http://forum.unity3d.com/threads/65707

A better grass tiling ground texture
http://forum.unity3d.com/viewtopic.php?t=63754

Free Simple Building Kit
http://forum.unity3d.com/threads/68986

Free Unity package – 100+ Medevil RPG 3d Models, with Diffuse Normals and Light Maps

http://forum.unity3d.com/threads/74921

Free RPG models
http://forum.unity3d.com/threads/58941-free-rpg-models…

Free sword collection

http://skies.lemuria.org

http://www.3delyvisions.com

Free 2D sprite animations
http://forum.unity3d.com/viewtopic.php?t=64565

Free Pacman graphic
http://forum.unity3d.com/viewtopic.php?t=48259

Unity3D.com Assets
http://unity3d.com/support/resources/assets/

Forest trees collection

http://forum.unity3d.com/viewtopic.php?t=59839

Low Poly Fir Tree
http://3docean.net/item/low-poly-fir-tree/75386

Road segments
http://forum.unity3d.com/viewtopic.php?t=61185

Frozen Orb Skill Prefab (Diablo2)
http://forum.unity3d.com/viewtopic.php?t=63621

Unity 3d Pack of Vehicles, packs of house & cities
http://unity3dres.narod2.ru