Git .Net files to ignore
This is not really git-specific, but rather applies to any version control.
Ignore the bin and obj folders, and the .user and .suo files (which are user-specific). That is, of course, if you're using Visual Studio.
An initial list excludes all temporary build files,
*.dep *.aps *.vbw *.suo *.obj *.ncb *.plg *.bsc *.ilk
*.exp *.sbr *.opt *.pdb *.idb *.pch *.res *.user
Also the build directories
*\obj
*\bin
*\Debug
*\Release
if you use Rehsarper, exclude its directories too
./Resharp*
Plus some special files
Thumbs.db
Some people also exclude binary files
*.exe
*.dll
It might be worthwhile considering what you want to store in your SCM, rather than a long and possibly never-complete list of exclusions.