All of the links consist of free 3D assets and tools that I find it useful for my game development. Will keep updating once I found any good stuffs online.
3d Game assets
https://www.turbosquid.com/ - put the price as 0 - 0 to search.
https://sketchfab.com - search with ‘downloadable’ option. Also have lots of photogrammetry models. Take note of the license
https://gumroad.com/discover?maxPrice=0&minPrice=0&query=3d%20model&sort=price_asc&tags=# - search free 3d models with price $0 and low to high option
Textures and Materials
https://share.substance3d.com/ - Really great website, recommend it.
https://hdrihaven.com/ - free HDRI
https://source.substance3d.com - check the freebies
https://gametextures.com/shop - check the freebies
https://www.mixamo.com/ - all free animations.
https://mocaponline.com/collections/archviz-animations - some free ones.
http://www.evolved-software.com/treeit/treeit - make trees (Haven't tried it yet!)
http://graphics.uni-konstanz.de/~luft/ivy_generator/ - generate ivy, not bad but needs some cleaning up with the poly count.
http://www.fromtexttospeech.com/contact_form.php - maybe for voice acting?
https://www.audacityteam.org/ - sound/music editor.
https://freesound.org/ - search with Creative Commons 0 .
https://motionarray.com/browse?free=true - free bunch of stuffs including audio/videos
Plugins/tools for Unity
https://unitylist.com - users created projects, shaders etc
https://gist.github.com/nukeop/1d2e54bed93ca7e5a67794e45a402541 - dissolve shader.
https://github.com/ZGeng/DeepSnowFootprint - tried it but.. Some limitations.
https://github.com/keijiro - tons of really cool effects but haven’t try it all.
Google doc - free document maker
Google drive/ drop box - storage