99% btc gambling ivstemnet website is scam to beware before invert any btc on any website it get ur btc and dont give anything
OP is interested in knowing which is the best site for gambling online and not for investing money in casino bankrolls and I do agree that its hard to find genuine site to invest our bitcoins as most of them will turn scam in long run.
It is very clear that the OP stated he wants to invest and not to gamble, investing in a casino bankrolls a good idea you only need to choose a casino that is reputable and that is not going to run away with your money. Read this thread.
https://bitcointalk.org/index.php?topic=1585408.0