Just found Jetbrains dotPeek

Now I feel like a hacker

It's a great tool, but it's not perfect. There are a few different disassemblers and they differ in how they convert some IL constructs into code. So especially when you export code to a solution, it may be useful to replace code that can't be compiled with code generated by different tool. I've used disassembling tools pretty often to understand how things work and once even to find a bug and then fixed it via reflection.

@CWins Can you recommend any other decompiler for c#?