Sportsbook and Superbook= horrible... slow payouts, shytty customer service, and you have to send them a bunch of shyt for them to even process your payout (license, utility bill, etc.
Bookmaker= half decent... accepts visa, decent payout system (always request your money from moneygram or western union though, the checks take forever and I had one that bounced)
5dimes= Great, fast payouts, excellent lines and parlay options and decent payout system
Youwager= half decent, low deposit minimum, great customer service, fast payouts
(they do request a bunch of documents in order to receive payouts if you deposit using Visa though)
I hear betislands is decent but I haven't used them, I'm at work so if you have any questions about the books I mentioned post them and I will answer them later.