Looking at the dates of peerbet and bit77 and bitcoinvideocasino they all date later than satoshidice so maybe we can considered them as well. I still can't believe satoshidice was sold for 126k bitcoins, that is equal to more than 440 million dollars right now, HALF A BILLION DOLLARS. It is insane that a casino in bitcoin world got sold for that much money.
I hope the casino world here gets bigger and gets a wider because lately "trading" got more famous than gambling for some reason and it got more attention than casinos which lowered the hype for it.
your right satoshidice is oldest.
i'm glad Bitcoin Video Casino is still around. i remember winning 2 BTC on slot jackpot in 2015