BetOnline (SBR rated A-) currently has no complaints levied against them and no processing issues to speak of at this time, which is a positive these days. The limits are $2,000 (Sides & Totals) which isn't bad at all really, however they will collar you if you start to beat them up at a pretty good clip. So needless to say they are a recreational book.
Their are a couple of things I don't like is that they charge $50 for fedex checks and they don't do book-to-book transfers. (Sucks they don't accept Moneybookers for Canadians).