title: Best Collection for Fast String Lookup
body: <p>I need a list of strings and a way to quickly determine if a string is contained within that list.</p>
  
  <p>To enhance lookup speed, I considered <code>SortedList</code> and <code>Dictionary</code>; however, both work with <code>KeyValuePair</code>s when all I need is a single <code>string</code>.</p>
  
  <p>I know I could use a <code>KeyValuePair</code> and simply ignore the <code>Value</code> portion. But I do prefer to be efficient and am just wondering if there is a collection better suited to my requirements.</p>