I had some free time and i went ahead and made the chart that i meant above.
I believe this is much more informative than just having the chart for total profit:
p.s. i could not continue past week 10 since new casinos were added and the investment amount was changed.
CryptoGames seems to have the most stable pattern in regard to profits earned, never giving a hiccup. Betking earned greatly on primarily two occasions, but other than that, it is hardly better than CryptoGames and SafeDice. SafeDice itself might be the best choice with CryptoGames being second best. Its profit variance is higher than at CryptoGames but profits themselves are higher too, at least, as far as we can judge by the chart. The rest are just not worth our attention and money.