I've been with WagerStreet for about 3 years now. They have both a sportsbook and online casino. It is run by a native american tribe in Canada, as opposed to the offshore locations of most places. I've never had a problem at all in the entire 3 years (and the casino appears to be legit as far as odds go - I play video poker a lot and would likely be able to tell if they were cheating).
Brad