I am surprised at the number of early responses from people who prefer to take a break, or the one guy who said they wouldn't read series books.
Almost everything I have read has been a series book.
Anyways...
I prefer to read them in series, to keep them fresh in my mind. Of course obviously you can't always do that. Some authors don't have all their books completely, if it's a new series.
Some of them I will re-read before the new book comes out, just to keep it fresh.
For example, it has become a ritual for me to re-read the Wheel of Time before each book comes out, because the series is up to 11 books now, and it's become impossible for me to remember all the little side plots without re-reading before each book.
In fact, I find it very frustrating waiting for the new books to come out. For me, it doesn't highten my anticipation, it frustrates me because sometimes I'll completely forget about a series for reading other books, and then sometimes even 2 or more books will be released before I remember to come back to it.
Currently I was reading some new dragonlance novels the series is called the Dark Disciple and 2 books have been written and the series is unfinished. Currently the author is also working on another series, the first book of which is called, "dragons of the dwarven depths". The author is Margraret Weis, and from what I understand she has put off Dark Disciple until the other series is done.
I find this very frustrating as a fan, that she would commit herself to two series and actually put one off to finish another. I can understand the need to keep your mind active by switching projects once in a while, but it seems to me that if you commit to a series, you should finish it and if you DO start another project while working on a series, you should work on them simultaneously instead of putting one off.
Mathius