When it comes to an organisation looking after your money, I think you really have to be 99-100% sure that they are legitimate. Top sites with good reputations include all the "biggies" like Party, Poker Stars
, Ultimate, FTP, etc. It's best to steer clear of small, less established sites asking you to send highly confidential info in my opinion (this is why I didn't touch Mansion Poker
with a barge pole).
Sites connected to UK betting companies like Coral, William Hill
, Ladbrokes and Paddy Power Poker are also pretty secure and reliable.