Explanation:

First we are creating the  MembershipUserCollection Object and Filling it with All Registered users using Membership Object GetAllUsers(); method.

For creating the Sorted list we need a DataView Object which will be created through Filling a DataTable from all users data.

public DataView GetAllUsersDataTable()
{
     MembershipUserCollection mc = new MembershipUserCollection();
    mc = Membership.GetAllUsers();

    DataTable dt = new DataTable("LastUsers");
   dt.Columns.Add("UserName", typeof(string));
   dt.Columns.Add("Rdate", typeof(DateTime));

   foreach (MembershipUser st in mc)
  {
      dt.Rows.Add(new Object[] { st.UserName, st.CreationDate });
   }

   dt.AcceptChanges();
   DataView dv = new DataView(dt);
   return dv;
}

Now we will sort the DataView on users Registration data. (Descended i.e last registered 1st)

DataView tView = GetAllUsersDataTable();
tView.Sort = "Rdate DESC";

GridView1.DataSource = tView;
GridView1.DataBind();