There are lot of best casinos nowadays and there are even more new casino appears in everyday. Primedice, Cryptogames, Bitsler, Bitdice, Fortunejack, as known as reputable and trusted gambling site since years ago. Stake, Windice, Onehash still considered as new gambling site/casino, but but you can trusted them too.
Lots of choices actually and you can able to find these gambling sites by just looking into the boards of this forum alone.
It depends on what gambling games you are into.If you do seek for Dice games or Sportsbooks then we do have lots of it.
The choice would depend on how those sites would suit your needs.