I always find threads like this surprising. Different products obviously serve different niches. If you want to write C# or VB on an embedded device, a Netduino is a natural. (I must concur with some others here who have stated they would rather chew off their own right arm, but I do appreciate that it is largely a matter of taste. My right arm tastes terrible, however.) If you want to run a full version of linux on a SoC device, the RPi takes on all comers in the embedded linux bang for buck metric. If you want to learn 8-bit embedded programming using something very similar to but not quite C/C++, the Arduino Uno is your answer. And so on.
Why the "my device is better than your device" mentality? You can make all (or none) of the various options available "your device" if you so choose.
If I ever feel the need to C# or VB, I'll get back to you. Mostly 'armless.