My vote is for Robin Hobb's DRAGON KEEPER.
I haven't read Red Claw, so I can't make any arguments as to why Dragon Keeper is better, so let's stick to undeniable facts:
1. Just two months after its release in the US it already has 62 reviews with an average rating of 4 stars. Red Claw has been out for five months and only has 6 ratings with an average rating of 3.5 stars.
2. Robin has a fan club!
Search her name and you'll find not only a prolific number of books, but also
theplenty.net, a fan club full of people devoted to discussing her previous books and the most recent book, Dragon Haven. Only an amazing author would draw such a following.
3. Further attesting to Hobb's popularity and skill as a writer is a graph showing the search volume overtime in Robin Hobb's name verses Philip Palmer.
Check it on Google Insights.4. As of 2003 she had sold over 1 million copies of her first nine novels. Boom!
On a more personal note, Robin Hobb's Dragon Keeper is an accumulation of years of world building and character development. Dragon Keeper is not simply a book, it is the climax of dragon lore that has been built up over thousands of pages in her previous books. The reason she has so many fans is because one can not read one of her books without establishing a strong personal attachment to her characters. She does not write stories. She creates legends.