Question of the Week: What is your favorite trilogy?

I read a lot of trilogies, and I often find that I love the first book in the trilogy, am slightly disappointed in the second, and really like the third one. Here are some trilogies that I enjoyed:

1.Smitten  2.Secretly Smitten  3.Smitten Book Club

1.Proof  2.Poison  3.Peril

1.Hostage in Havana  2.Murder in Miami  3.Payback in Panama

                       1.Lightkeeper's Daughter  2.Lightkeeper's Bride  3.Lightkeeper's Ball

                   1.When the Smoke Clears  2.When a Heart Stops  3.When a Secret Kills

What are your favorite trilogies?