public class SomeClass
        {
            public int ID { get; set; }
            public string Value { get; set; }
        }

        public class SomeClassComparer : IEqualityComparer<SomeClass>
        {
            #region IEqualityComparer<SomeClass> Members

            public bool Equals(SomeClass x, SomeClass y)
            {
                return (x.ID.Equals(y.ID) && x.Value.Equals(y.Value));
            }

            public int GetHashCode(SomeClass obj)
            {
                object temp = obj.ID + obj.Value;
                return temp.GetHashCode();
            }

            #endregion
        }

        static void Main(string[] args)
        {
            List<SomeClass> list = new List<SomeClass>();
            list.Add(new SomeClass() { ID = 1, Value = "qwe" });
            list.Add(new SomeClass() { ID = 2, Value = "asd" });
            list.Add(new SomeClass() { ID = 3, Value = "zxc" });
            list.Add(new SomeClass() { ID = 4, Value = "qwe" });
            list.Add(new SomeClass() { ID = 1, Value = "qwe" });

            Console.WriteLine("Original list:");
            list.ForEach(a => Console.WriteLine(string.Format("{0} - {1}", a.ID, a.Value)));

            Console.WriteLine(Environment.NewLine + "Distinct list:");
            list.Distinct(new SomeClassComparer()).ToList().ForEach(a => Console.WriteLine(string.Format("{0} - {1}", a.ID, a.Value)));

            Console.ReadKey();
        }