Avoid Reactor. It is completely useless (and yes I paid for a license). Xenocode was the best one I encountered and bought a license for too. The support was very good but I didn't need it much as it just worked. I tested every obfuscator I could find and my conclusion is that xenocode was far and away the most robust and did the best job (also possibility to post process your .NET exe to a native exe which I didn't see anywhere else.).
There are two main differences between reactor and xenocode.
The first one is that Xenocode actually works.
The second is that the execution speed of your assemblies is no different. With reactor it was about 6 million times slower. I also got the impression that reactor was a one man operation.
