such as rollbit, even freebitcoin has a good casino that you can gamble, so for me I prefer all the casinos here more than the ones that I'm not familiar with.
Can't say anything about Rollbit as I haven't used it but I won't suggest anyone to use freebitco.in as users were having some issues with that site and many of those created scam accusations against that site. Most other casinos that have announcement thread on this forum and are activity spending money for advertising should be good options for OP.