Hello friend
Pls without referring to any particular site can anyone offer a less bias advice as to how they select a very good gambling like what are their features, advantages and disadvantages, how successful has there decision been so far and so on
Almost everyone here wears signature so I don't know how you'll trust us but I'll still give you advices, if you want consider them despite my signature.
At first good gambling website must be highly secured, instant deposit/withdrawals and good support. This three is must to have to my mind.
Then everything depends on what are you looking for. Many website has different promotions. For example bitsler has daily, weekly, monthly wager contests and so on, bitdice has rakeback system, Fortunejack has deposit bonuses...
When you decise to gamble on website, check if they have ANN thread on bitcointalk, what's trust of ANN thread creator and also see if there was open amy scam accusation thread against them, why and how it was solved.