I'm looking for a good book; it occurs to me that one type of book I enjoy is when an old story /legend is told from a different perspective. Like 'Mists of Avalon', which is the King Arthur tale told by his sister.  or 'Ahab's Wife'.

Any ideas?

i loved The Garden by Elsie V. Aidinoff.  it is eve's point of view from the garden of eden. it actually is a young adult book, but doesn't read like one.

You might like Wide Sargasso Sea by Jean Rhys.  It's not a retelling of Jane Eyre, but it is written from the perspective of the woman in the attic in Jane Eyre.

Almost any of Greg Maguire's books : Wicked, Confessions of sn Ugly Stepsister, classic tales from the side of the accepted "villain".

Margaret

Well. . . Jacqueline Carey's Banewrecker/Godslayer duology should fit. It's Lord of the Rings cast as a tragedy, so most of the main characters are on the side of darkness (or at least, the rest of the world perceives them as villains). It's not quite as obviously a retelling as the other titles mentioned, because Carey opted to rename some of her races and develop a different mythological back story, but in its outline it is definitely Lord of the Rings. (It's also quite excellent, and doesn't have anywhere near as many hot-button issues as Carey's main series, Kushiel's Legacy.)

Jack Whyte's Skystone series is another re-telling of the King Arthur tale--the first book is told by Arthur's grandfather, and later books are told by Merlin. I think they're quite good!

March by Geraldine Brooks is the story of what happened to the father from Little Women during the Civil War, told by Mr. March himself. Another excellent book, and I loved getting a perspective of the March family from a character who's pretty quiet in the original book.

I know I've read a couple other good ones but it will take a little brainwracking to pull them up!

I love this type of story too - especially retellings of fairy tales - so this'll be a long list :)

Mary Stewart's Merlin series (The Crystal Cave, The Hollow Hills, The Last Enchantment, etc.) has been one of my favorites for a while, narrated by Merlin.  It tells of his childhood, how Uther Pendragon and his brother Ambrosious conquer England, how Merlin orchestrates Arthur's birth, then how Arthur grows and becomes king.  A subsequent book, The Wicked Day, deals with Mordred's rise and Arthur's fall.

Donna Jo Napoli does a lot of retellings.  The Magic Circle is my favorite, told by the witch from Hansel and Gretel.  It's the backstory of how she came to be in the candy house in the woods.  Zel is Rapunzel told from the shifting perspectives of Rapunzel, the witch, and the prince, also very good.  Her books are aimed at young adults or children but they're still enjoyable as adults.

Neil Gaiman - "Snow, Glass, Apples", a short story from his Smoke and Mirrors collection, I think you can guess what fairy tale this is about.  It's only 20 pages from the perspective of the evil stepmother but it's so good, you'll never look at the original the same.  I can't recommend it highly enough.

If you like Pride & Prejudice there's probably a million retellings out there from Darcy's point of view.  My personal favorite is the Fitzwilliam Darcy trilogy by Pamela Aiden (An Assembly Such as This, Duty and Desire, These Three Remain).  Aiden gives him an awesome valet and Georgiana comes into her own.  Darcy's off doing his own thing for most of Duty and Desire, but the 1st and 3rd books closely follow the original plot with some additional Darcy and Elizabeth scenes thrown in.  I've reread the last book so many times; it makes me fall in love with Mr. Darcy all over again every time.

The following aren't retellings from a different person's point of view, but are reimaginings of classic stories: Robin McKinley (one of my favorite authors, anything she writes is awesome) has 2 tellings of Beauty & the Beast - Beauty and Rose Daughter, both different enough to be enjoyable.  She also has The Outlaws of Sherwood about Robin Hood (love this story!) and Spindle's End about Sleeping Beauty.  My favorite book of hers (and one of my favorite books period), Deerskin, recasts Donkeyskin, a lesser-known classic tale by Charles Perrault.  There's some adult content (not any romance novel type stuff, just adult themes) but the characters and story are fantastic.

Donna Jo Napoli also has a Beauty & the Beast adaptation (titled Beast, I think) where the Beast is a Persian prince who travels to France to find his Belle.  Also Spinners about Rumpelstiltskin, though I didn't like that as much.

I forgot: Grendel by John Gardner.  Told in first person narration by Grendel, it's irreverent, cynical, touching, and utterly absorbing.  It's now often taught in schools as a classic in its own right.

How about   Was  by Geoff Ryman.   Very interesting retelling of the Wizard of Oz in the present day context.  Deeply dark, but very well done.

http://www.paperbackswap.com/book/details/163883-Was

Oooh, I like this kind of stuff too, mostly the fairy tale retellings. I took a class on fairy tales in college (yeah, it was like the best class ever) and our textbook was The Classic Fairy Tales edited by Maria Tatar, which included a lot of different versions, in particular some surprising ones, of well known stories. Some of my favorites were the sections on Beauty and the Beast and Snow White, cause they included stories that were very interesting takes on the originals. (Needless to say, I decided to keep that book after the class was over!)

This MetaFilter thread also has a lot of great suggestions that I've gotten a lot of books from: http://ask.metafilter.com/60447/Fairytales-for-grownups

Edit: I can't believe I forgot to mention Ella Enchanted by Gail Carson Levine! A retelling of the Cinderella story, one of my favorite books when I was younger; it's young adult but still holds up. If you somehow haven't read it already, read it. And if you've seen the movie, it's about as far from the book as a movie could possibly be. 

March was good, it was Mr. March's (or the dad) side of Little Women.

Ice- Sarah Beth Durst

its considered YA but I really enjoyed it. Its a retelling of the folk tale East of the Sun, West of the Moon.

The true story of the three little pigs- Jon Scieszka 

Told from the wolf's perspective.  One of my favorites.

Enchantment by Orson Scott Card was wonderful.  It's the Sleeping Beauty story, told about a modern scholar from today-ish who finds Sleeping Beauty centuries after the curse.  It goes between two worlds, hers and his, and draws on some influence of the Russian style of fairy tales.   I just finished it while on vacation, I thought it was fabulous (like his other books!).

I've always loved this type of book as well! 
You may want to look at compilations as well-- such as Ellen Datlow and Terrie Windling's rewritten fairy tale series (one title that comes to mind is Ruby Slippers, Golden Tears)
Tanith Lee is also very good at rewritten tales.

I second Gregory Maguire, but note that his tales tend to be very dark. I didn't enjoy Wicked as much as I thought I would (very negative/dark book) though I loved the musical...

Good Luck!