Thanks to Dror A. for bringing this issue up.

from MSDN:

Even though Singleton is a comparatively simple pattern, there are various tradeoffs and options, depending upon the implementation. The following is a series of implementation strategies with a discussion of their strengths and weaknesses.

Simple Singleton:

using System;

public class Singleton
{
   private static Singleton instance;

   private Singleton() {}

   public static Singleton Instance
   {
      get 
      {
         if (instance == null)
         {
            instance = new Singleton();
         }
         return instance;
      }
   }
}