using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<Person> person = new List<Person>();

        person.Add(new Person(){ Name = "Nada", Age = 25 });

        person.Add(new Person(){ Name = "Mike", Age = 30 });

        person.Add(new Person(){ Name = "Nada", Age = 25 });

        //person = null;

        //person = person.Where(x=> person.Any(dup => x.Name == dup.Name)).ToList();

        person = person.GroupBy(x=> x.Name).Select(s => s.First()).ToList();

        Console.WriteLine(person[0].Name);

        Console.WriteLine(person[1].Name);

        Console.WriteLine(person.Any(x => x.Name == "Nada"));

    }

}

​

public class Person

{

    public string Name {get; set;}

    public int Age {get; set;}

}