using System;
using System.Linq;

public class Test
{
	public static void Main()
	{
var list1 = new[] { new { ID = 1 }, new { ID = 2 }, new { ID = 3 } };
var list2 = new[] {
	new {
		ID = 1,
		Name = "Jason"
	},
	new { 
		ID = 1,
		Name = "Jim"
	},
	new {
		ID = 2,
		Name = "Mike"
	},
	new {
		ID = 3,
		Name = "Phil"
	}
};

var lst = (
	from lst1 in list1
	join lst2 in list2 on lst1.ID equals lst2.ID into lstGroup
	select lstGroup.First()
);

		foreach(var item in lst)
		{
			Console.WriteLine("ID: {0}, Name: {1}", item.ID, item.Name);
		}
	}
}