What types of files/folders should I exclude/ignore for committing Unity projects to GitHub?

Since I just started on Unity, I would like to get the hang of source control by understanding what files can be ignored and what files are crucial for development.

Does anyone have a list that I can copy/paste from? And if possible, can someone explain what particular ignored files/folders are and what they do that warrants a .gitignore entry?

 

Google "unity gitignore"

Github has sample one.

The current approach of checking in the entire assets directory is very resource heavy.
I am experimenting with an alternative that does not check in pre-built packages - here is link to post:
http://forum.unity3d.com/threads/version-control-and-asset-packages.327669/

 

It would seem that Unity 5 may have dependency changes in regards to source control packages and what to exclude.

Also, since you have linked to another recent thread about controlling asset packages not needed to check in, I guess my thread is kind of moot.