So much evil...

gistfile1.cs

using System;

namespace Evil
{
    internal static class Program
    {
        private static void Main(string[] args)
        {
            Evil x;
            MoreEvil y;

            // Prints True, False
            Console.WriteLine(x == true ? true : false);
            Console.WriteLine(x ? true : false);

            // Prints False, True
            Console.WriteLine(y == true ? true : false);
            Console.WriteLine(y ? true : false);
        }
    }

    public struct Evil
    {
        public static bool operator true(Evil x)
        {
            return false;
        }

        public static bool operator false(Evil x)
        {
            return true;
        }

        public static bool operator ==(Evil x, bool y)
        {
            return true;
        }

        public static bool operator !=(Evil x, bool y)
        {
            return false;
        }
    }

    public struct MoreEvil
    {
        public static Evil operator ==(MoreEvil x, bool y)
        {
            return default(Evil);
        }

        public static Evil operator !=(MoreEvil x, bool y)
        {
            return default(Evil);
        }

        public static bool operator true(MoreEvil x)
        {
            return true;
        }

        public static bool operator false(MoreEvil x)
        {
            return false;
        }
    }
}