using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Test theOne = new Test

        {

            ID = 3,

            CountryID = 80,

            LanguageID = 12

        };

        List<Test> list = new List<Test>();

        list.Add( new Test { ID = 5, LanguageID = 10 } );

        list.Add( new Test { ID = 3, LanguageID = 11 } );

        list.Add( new Test { ID = 1, LanguageID = 12, CountryID = 80 } );

        list.Add( new Test { ID = 2, LanguageID = 13 } );

        list.Add( new Test { ID = 12, LanguageID = 12 } );

        list.Add( new Test { ID = 6, LanguageID = 14 } );

​

        list = list

            .OrderByDescending( x => x.ID == theOne.ID )

            .ThenByDescending( x => x.CountryID == theOne.CountryID && x.LanguageID == theOne.LanguageID )

            .ThenByDescending( x => !x.CountryID.HasValue && x.LanguageID == theOne.LanguageID )            

            .ToList();

        foreach( Test item in list )

            Console.WriteLine( item.ID.ToString() );

        Console.WriteLine( "Choose: " + list.First().ID );

    }

}

​

​

public class Test

{

    public int? CountryID;

    public int ID;  

    public int LanguageID;

}