For me, I would have to say Margaret Weis and Tracy Hickman. Nothing against them, but I could never get into any of the things they wrote. I started reading Dragonlance stuff, but not with work they had written. I just never liked their stories and whenever I see their names it turns me off. I dont know why. I don't hate them or anything and I applaud them for their huge success (they've done a great job, after all), they just never appealed to me.
And I also don't like David Eddings. That might be because I have only read one book by him and it was one of his later books, but it was horrible and I can't bring myself to try his earlier stuff yet.
Lastly, which will probably make you all despise me: J. R. R. Tolkien. Yeah, I know, he's wonderful and stuff, but I can't stand his writing. The story is awesome, but he couldn't write worth crap and I'm not going to pull my punches on this. His books are not that great. He spends way too much time babbling to doing things that are annoying and there isn't enough action. Too much description. I love the story, I do like the detail, but I can't stand his writing style and have only read LOTR once and never will again. Sorry, that's the truth. If I need a LOTR fix for some reason, I go to the movies. The LOTR movies are a rarity because they may be one of the first incidences where the movie was far better than the book.
But that's just me. Anywho!