I know so many people who won't start reading a series if they can't read them in order from the beginning. This often knocks them out of some really good reading. I was happy to find re-issues of the beginnings of two popular series in my mail recently.
Introducing Aunt Dimity, Paranormal Dective by Nancy Atherton (Penguin) is a trade paperback with the first two Aunt Dimity titles, Aunt Dimity's Death and Aunt Dimity and the Duke.
First Degree, Open and Shut, and Play Dead by David Rosenfelt (Grand Central Publishing) are all in paperback (the first two are at a special $4.99 price). This is one of my favorite legal series. Try it—you'll like it.