using System;

using System.Linq;

using System.Xml;                   

using System.Xml.Linq;

using System.Collections; 

using System.Collections.Generic;

using System.Data;

using System.Data.DataSetExtensions;

using System.Data.Linq;

using System.Text;

using System.Text.RegularExpressions;

//using System.Collections.Immutable;

​

public class Program

{

    public static void Main()

    {

        string input = @"<preferences>

  <section name=""PREF_SECTION_NAME_1"">

    <preference name=""PREF_EXAMPLE_1"" type=""radio"">

      <default value=""true""></default>

    </preference>

    <preference name=""PREF_EXAMPLE_2"" type=""radio"">

      <default value=""true""></default>

    </preference>

    <preference name=""PREF_EXAMPLE_3"" type=""radio"">

       <default value=""true""></default>

    </preference>

  </section>

  <section name=""PREF_SECTION_NAME_2"">

    <preference name=""PREF_EXAMPLE_1"" type=""radio"">

      <default value=""true""></default>

    </preference>

    <preference name=""PREF_EXAMPLE_2"" type=""radio"">

      <default value=""true""></default>

    </preference>

    <preference name=""PREF_EXAMPLE_3"" type=""radio"">

      <default value=""true""></default>

    </preference>

  </section>

</preferences>";

        var xDoc = XDocument.Parse(input);

​

var sections = xDoc.Root

                  .Descendants("section")

                  .Select(x => new Section

                  {

                     Name = x.Attribute("name").Value,

                      Preference = x.Elements("preference")

                                    .Select(y=> new Preference 

                                            {

                                                Name = (string)y.Attribute("name"),

                                                Default = (bool)y.Element("default").Attribute("value")

                                            })

                                     .ToList()

​

                  })

                  .ToList();

        sections.Dump();

    }

}

​

public class Preference

{

    public string Name { get; set; }

    public bool Default { get; set; }

}

​

public class Section

{

    public string Name { get; set; }

    public List<Preference> Preference { get; set; }

}

​

public class Preferences

{

    public List<Section> Section { get; set; }

}