It gets even worse because Roxy Affiliates is going to be a single casino affiliate program for you if you´re smart. They bundle and therefore I would only promote Roxy Casino or Vegas Splendido.
Yes Kiwi does lack a bit in support but it´s one of the best Playtechs.
I forgot to mention Referback. That´s one I like. The gaming club, Riverbelle, Jackpot City in various languages and Lucky Nugget make this a really good program.
One I am personally not promoting but am contemplating to sign up to is tridentshare. King Neptune´s and VegasUSA look really slick.
Others I would consider are Casino Partners (Spam issue was annoying), Casino Profit share (you can promote the instant payouts), and maybe Income Access which gives you access to Lasseters and Jackpot Joy.
Please use my sign up link if Referback looks convincing 