Jude Watson - My favorite Star Wars writer as well as one of my favorite writers. Yes, her Star Wars books are written for children, but they're really amazing, and deserve a lot more credit then they are given. Plus, she is one of the few writers who actually captures Obi-Wan's essence(as well as the bond between Obi-Wan and Qui-Gon) and she wrote some of the best female, Jedi or otherwise, characters(Siri, Tahl, Cerasi, Darra, Bant, etc)
Matthew Stover - This man wrote two of the most beautiful Star Wars books ever, as well as some of the best composition I have ever read, and yet, he is little known while crappy writers like E.L. James and Stephanie Meyers get tons of recognition. People have certainly lost their taste.
Victor Hugo - Yes, many people know his work, but he doesn't nearly get the recognition he deserves, especially since he's one of the best classic book writers ever.
Garth Nix - While he does have a fanbase, he still doesn't get the credit for all of his amazing fantasy novels; I mean, seriously, this guy deserves to have a movie made out of his books(instead, we're most likely going to be given a Fifty Shades of Gray film...I feel sorry for those poor actors).
Nancy Farmer - Author of many great works- both fantasy and sci-fi- she is still not as well known as she should be. I mean, have you read her book? They're incredible.
Patrick Ness - Author of the very unique Chaos Walking trilogy, he has created a trilogy that tackled some very heavy subjects, made one of the most memorable and real characters in his leads Todd and Violet; I would love to read some more of his books, someday.
Libba Bray - I read her Gemma Doyle trilogy(the last two I read last year) and loved how she interwove a fantasy setting/different realm in with Victorian England, and how the girls were empowered individuals(though greatly flawed) and were all good friends(females having good friends that they stick by and have a good relationship with are quite rare in YA nowadays).
Laurie Halse Anderson - I've only read her book, Speak, (though I plan on reading more), she managed to take a very bad topic(one I hate) and actually write it in a way that didn't belittle the main character, which was something I really appreciated, since most books don't do that.
Arthur Miller - A play write, but sadly not as well known as he should have been. My personal favorite script writer, he has written some of the darkest, most emotion pieces of theater I've come across, and he has some of the best written dialogue for a play I've ever seen.
Kevin J. Anderson - While a pretty good name in the Star Wars universe of writing, I get the sense that he isn't as respected as some of the other ones, and that is a shame since he's written some great SW books, especially the Young Jedi Knights series, which was a favorite of mine when I was younger(and still is among my favorites)
Isla J. Bick - While I've only read one book by her, I can already tell she's a talented author and can write something on a difficult subject and put forth a complex issue where you don't know who's lying, and it's really quite chilling.
On a side not, I really wish people would read Suzanne Collins' Underland Chronicles; while I do love The Hunger Games trilogy(especially the second and third), I felt this earlier work was better written and could have made some awesome movies. :D.
http://mixlr.com/channel-1138/showreel/geek-girl-radio-6/
Here's last week's podcast; sorry I'm so late in posting it.