Series? Or Stand-alone books?
My all time favourite books are stand alone and my favourite authors write only stand alone. In these cases I think that turning the books into a series would dilute the goodness of the book. One example is my favourite from last year "The Lacuna" by Barbara Kingsolver. It had so much packed into it and I loved every second of reading it. In my mind the ending is clear (although if you have read it you can see why some people might not think so). I think to pick it up again and continue with it would spoil it somehow. There is no way a second book would be as good as the first. The same is true of another book I recently read by this author "The Poisonwood Bible". Again a lot packed into it and you can tell a lot of love went into these books. The ending is clear and I wouldn't want to read a second book even if it wasn't. I know that the second book wouldn't be as good as the first. Favourite authors who only write stand along include Haruki Murakami, Douglas Coupland, Margaret Atwood (for the most part), John Irving, David Mitchell and Ian McEwan. I would rather see what their imagination next brings rather than another installment of one of their previous books. Maybe because I have read so many of their other books that I know the next one will be as different as the others.
That's not to say I don't like a series. I actually enjoy a series as much as I like a stand alone. It's comfortable. You pick up a book in a series you love and you already know most of the characters. You might not know what's in store for them but everything else is familiar. It's relaxing and I suppose could be described as comfort reading. How many of us love a good boxset? It's the same thing. You don't need to think too much and when you have had a stressfule day there is nothing better. The Stephanie Plum series by Janet Evanovich is a good example of that for me. I know all the characters. I can probably predict what is going to happen. Yet I still love them. Some series have more to them than that. The Thursday Next series by Jasper Fforde is another favourite. Not quite as predictable and has lots of little detail that keeps interest going each time. I do feel though that when a series has lost it's mojo maybe it is time for it to end. I believe that it should end on a high with the readers still wanting more rather than once the readers are bored with it. Oh, and end it with a bang too. The Stephanie Plum series can be used here again. It has lost something. The last few books have been a little more than predictable. The only reason I read them now is for the exploits of Grandma Mazur (and the delightful Ranger). I thought the Thursday Next series was going down that way too but if you have read my review of the last book you will know I have since changed my mind.
So to finally answer the question, stand alone or series, it's all about mood. They both have their good points and whilst series does have more bad points it has it's place. In need of comfort then pick up a series. In need of something with more kick then pick up a stand alone.