Example project in Unity3D to show how you should code and think if you want to obfuscate your c# code.
Obfuscation / Integer Masking library to encrypt numeric id to short string, generating a similar result to YouTube video id.
PEunion (Binder, Crypter & Downloader)
An Obfuscator for .NET assembly
Open source obfuscation tool for .NET assemblies
C# binary that mutates its own code, encrypts and obfuscates itself on runtime
.NET deobfuscator and unpacker.
Reads encrypted strings from obfuscated ConfuserEx assembly.