If you want good answers then you need to ask good questions. "best", "fastest" and similar ...st criteria generally depend on the details of what you want to do. Very often there is no '...st' answer, even in a well defined context. Taking that on board, would you care to rephrase your question providing a little more detail concerning the matches you wish to perform? Some important details are:

• Are you matching fixed strings?
• How many different match strings are there?
• How many elements do you need to match against (is 200M 200e6 elements, 200 MB, something else)?
• Is this a one time task, or do you need to run the matching process many times?
• What are the actual time constraints?
• Is there existing code that this needs to work with?
• Does the data come from something like a file or do they come from a database?
• Is it possible to put the data into a database if it isn't already?