I really like the subreddit over at http://www.reddit.com/r/asoiaf for theory discussion. They really dig deep sometimes, but its still fun
Super tinfoil-ey theories some of them. Ajorah Azai and Bolt On, especially. The great thing is that they all seem plausible to some degree, from the sheer amount of hints dropped throughout the series by Gurm, so much that its difficult to predict which ones are going to be even remotely true.