Sequels - How Many Is Too Many?

Planning a sequel to a novel is possibly one of the most fun experiences I've ever had as a writer.  Bringing back old familiar faces you love and creating new ones to spice things up and exploring character relationships further than you've ever done before.  After planning the sequel to An Imperfect Fairytale, I can't imagine never writing about Rowena and Artem ever again but that also brought up another question in my head.  Can you ever have too many sequels?

I hear people say all the time that a sequel is never as good as the original, whether it's about books, movies or television.  In quite a few cases I agree.  I wish I had never watched Mulan 2 and the Roman Mysteries novels began to get on my nerves pretty quickly.  And yet there are some series that I can never get bored of.

The Song of the Lioness
by Tamora Pierce

The Tortall novels by Tamora Pierce have never failed to keep me enthralled with such wonderful world and the characters that inhabit it and it is one of the longest collections I have ever read. Currently, Tamora Pierce has written sixteen novels set in Tortall, starting with The Song of the Lioness quartet and ending with her most recent novels focusing on the character of Beka Cooper.  So how on earth does she keep me coming back for more?

Protector of the Small
by Tamora Pierce

I personally think it's the change of focus that keeps readers interested.  Focusing different quartets on different characters allows the reader to look at different characters in the same situation.  For example, her opening quartet The Song of the Lioness, followed the adventures of Alanna of Trebond, a girl who wanted to become a knight in a time when only boys were trained to fight.  The story takes us from Alanna aged 10, dressing up as a boy, all the way through her many adventures until...well I'm not going to tell you what happens at the end because that would spoil it.
As a follow up to the we get the Protector of the Small quartet where we are introduced to Kel, a young girl wanting to follow in Alanna's footsteps and train to become a knight.
All the series of Tortall novels link together in some way.  Beka Cooper, whose story takes place a hundred years before the opening of Song of the Lioness, is even an ancestor of the Rogue, George Cooper.

True Blood; my not-so-secret guilty pleasure.  Everything about these books tells me I shouldn't like them in the first place, let alone keep coming back for more, so why on earth does Charlaine Harris have me hooked?  It certainly isn't the carefully constructed dialogue, beautiful description or elegant writing style, so what makes me crave another Sookie Stackhouse mystery.

Dead to the World
by Charlain Harris

In truth I don't think even I can answer this one.  Even the central character, Sookie, annoys me sometimes with her terrible dilemma of having every available man throwing themselves at her.  It is true that two are vampires and three are Shifters and they come with a lot of baggage, but it still annoys me how she can never make up her mind which guy to go for.
The supporting characters are what make these books for me.  I thank Alan Ball every day for not killing off LaFayette at the end of the first season of the TV
adaptation like Harris did in her novel and Sam Merlotte, Jason Stackhouse and Eric Northman are all wonderful supporting characters.  They all seem to have far more personality than the two main characters, Sookie Stackhouse and Bill Compton, put together.  They are all individuals with their own problems to deal with, even if they are closely linked to Sookie and her strange ability to read minds.
But I think the thing I like about this series most is the fact that it doesn't hide what it is.  It boldly make the link between vampires, sex and drugs that has been implied throughout literature and media ever since Dracula was written in the 1800s.

Inkheart
by Cornelia Funke

And then there are other sequels that just don't stand up to the original.  For example, Inkheart by Cornelia Funke was a wonderful book.  I loved all of the characters from Meggie to Mo to Dustfinger to Farid to Capricorn to Gwin the Marten.  They all captivated me and drew me into a story I wanted to live in.  I can remember being so excited when the sequel, Inkspell, was published that as soon as I had a copy in my hands I began reading it immediately.  Although Inkspell didn't quite live up to its predecessor, it was still a decent read and so I waited in anticipation for the third and final instalment in the Inkheart trilogy.

Paul Bettany in the film adaptation
of Cornelia Funke's novel Inkheart

And I waited what felt like an eternity.  Admittedly two years isn't a long time to wait for a book to be published but when I finally had a copy of the third book, Inkdeath, in my hands I was a little disappointed.  The characters didn't really have the same vigour as they had at the beginning of the series and I didn't find myself glued to the page in the same way as when I read Inkheart.
And then to add insult to injury they pushed the novels even further by making a movie out of it.  Admittedly, if the film hadn't been based on the novel I wouldn't have minded so much, but as an adaptation of a novel it just didn't cut it for me.  The majority of the casting was genius.  I've got to love Jim Broadbent no matter what film he's in and Brendan Frasier surprised me as Mo.  But the ultimate casting has to go to Paul Bettany as Dustfinger.  He was exactly as I had imagined him and the fire eating scene just blew me away.

But it isn't just in the writing world where sequels are forced out when they really aren't needed, it happens in the theatre too.  Take Andrew Lloyd Webber's hugely successful musical The Phantom of the Opera, adapted from Gaston Leroux's novel of the same name, which has been running for 25 years in London's West End, bringing in millions of audience members from across the globe and being transformed into a film for people to watch on the big screen.  Even though the adaptation isn't strictly true to the novel it is still one of my favourite musicals on the stage.
But then a few years ago, Andrew Lloyd Webber had an idea; why not make a sequel?  This mad money-making scheme had not impressed me at all and when the production finally hit the London stage I was determined not to go see it.  The fact that the show, Love Never Dies, has gained the nickname 'Paint Never Dries' is enough to put most people off from going to see it.  I'm not criticising the music in any way, Andrew Lloyd Webber has created some of my favourite songs of all time and I'm sure the music for his newest production is wonderful, but I'm sure Gaston Leroux will be turning in his grave to hear that the character he killed at the end of his novel has been resurrected to star in a production with one of the flimsiest plots I have ever heard!

So I don't think I can say when authors should stop writing sequels.  Even when plots have been concluded some authors can still get away with writing another novel using the same location and characters as they did before when others can't.  What do you think of my choices?  Do you have any novels that you think never should have had sequels?  Or is there a book that you think should have had a sequel?