In our short track record, we have had good results with bodog. They have been pretty responsive and professional as well. While it is a small sample size, they have shown to be great at retention as well. However, they don’t have much of an affiliate site (no tracking, no banners without asking for them, etc.) which is a bit annoying since you have to wait until the 15th of the month to find out how you did for the previous month.
Players do seem to like their site quite a bit, they never seem to be mentioned first by anyone in their favorites list, but they always seem to be on the list.