My favorite fantasy series is the Harry Potter Series, I can not pick just one book out of the series as my favorite.
I love the Malazan series by Steven Erikson, one of the best series and writing I've read in a really long time, not one book in the series disappoints. And I've always loved the Shanarra series by Terry Brooks, all 20 billion of them. The Dark Tower books were pretty great from what I've read of them, really need to finish it though.
I think this would have to be mine, although I don't read a huge amount of fantasy - I used to read a lot of RA Salvatore stuff, and I've read two of The Witcher books and like everyone I've read GRRM now.
Nothing for me has ever seemed as interesting an actual story as this book though. So often with fantasy it feels like what keeps you interested is the world-building, or the wonder, and pure-and-simple escapism and badassery. This book does have all that, but has a really great personal story at the heart of it.
Maybe that's because the world is closer to the real world, as it's an alternate history set during the period around the napoleonic wars, where magic used to exist, but then disappeared, but is slowly returning. I find that a really tantalising setup, and the book really delivers on it, mostly because the author clearly did good research both on British and European history, but also on British folk traditions. She really captures one of my favourite things about British folk music, which is a sense of wildness in the landscape, where situations can move from normal to eerie to downright bizarre.
It's also a great book because it is just written in a very different way to most fantasy, which tends to range from workmanlike all the way up to overly-portentous, it's nice to read something that is so clearly fantastical, written in the style of the 19th Century realist novel (although some people may find the use of 19th century spellings ("shew") a bit over-the-top). It also helps make the novel feel grounded, which I think is essential to the story, it needs (and achieves) a sense of reality that could easily shift towards unreality at any moment.
Also I just found out the BBC are making it into a miniseries so that's pretty awesome.
@the_ruiner: The Dark Materials trilogy was indeed interesting; lots of religious metaphors. He went on to write some book about Jesus, on a dare basically. I don't see what made you go "yuck" at the end, and I re-read it within the last year. Care to elaborate.
I finished the GoT "quintuplogy" as it exists now (will continue onto the septuplogy if he doesn't die beforehand). I probably finished it in a little over a month, and I'm basically spent. That being said, I can't wait to see what it all wraps up with. I expect it to somehow wrap up with the Stark family reuniting and becoming some kind of horrific Frankenstein Monster family and using their Captain Planet-esque powers to take over the kingdoms, but that's too happy and concise an ending for Martin.
This is kind of a weird choice, but Lloyd Alexander's Prydain quintuplogy (yes, I'm serious) has held a special place in my heart. The second book is "The Black Cauldron" for you Disney folks. Don't know why it was the only one to be animated. Anyway, it's like a 2nd grade reading level fantasy series with a blend of LOTR and GOT and other fantasy stuff. A lot of good character development. If you have kids, they're an excuse to read them yourself.
Finally, "A Dream of Perpetual Motion". As your doctor, I prescribe you one full treatment. If you now or ever were depressed or felt dead inside, you will most definitely relate. Maybe it's just me, but it's a perfect book; good setting, good characters, good writing (both high-felutant and self-conscious).
PS Is high-felutant even a word? I searched, and the only hit was Urban Dictionary. I'm sure I've heard it used legitimately though - maybe it's foreign?
You should all read Joe Abercrombie. His First Law trilogy is really great, it takes old tropes of fantasy and subverts them in some really neat ways. His best stuff is his standalone work, though that is set in this world and after it I think, so it's best read in order. Best Served Cold and The Heroes are two fantastic books. The Heroes is a 600 page book all about one pointless war over a hill. It never gets boring though!
Also, I'm near the end of the second book of Robin Hobbs Farseer trilogy. Those books are really good at creating great characters and making them feel real. One downside they have is so far they feel a little bit...limited in scope? But I think it's a really good balance between the political dealings in George R R Martins books, and traditional fantasy.