I have a few actually. Sometimes it is just time for a series to end, and yes I get sad about it, but I am ok with it. Other times, though, I love the story and the author so much that I never want it to end. Here are some examples...
Blue Bloods series by Melissa De La Cruz
The Mediator series by Meg Cabot
Generation Dead series by Daniel Waters
Twilight series by Stephenie Meyer
If these authors just one day decided, you know what that isn't the end of that series. Lets keep writing more books I would jump up and down with glee and keep reading them forever. I mean even with Twilight. I know I am getting over my Twilight obsession especially with it coming to an end officially with the last movie, but if Stephenie Meyer finally finished Midnight Sun and decided hey lets keep writing more in other perspective or write a whole new story to add to the Twilight series I would DIE! I would never say enough is enough.
So are there any series that you love so much that you would love it if they became a never ending series? Let me know in the comments below =]