title: Remove objects with a duplicate property from List
body: <p>I have a List of objects in C#.  All of the objects contain a property ID.
  There are several objects that have the same ID property.  </p>
  
  <p>How can I trim the List (or make a new List) where there is only one object per ID property? </p>
  
  <p>[Any additional duplicates are dropped out of the List]</p>