I can suggest only reliadble slots. I myself playing from time to time and I tried different slots. To be honest, almost all of them are reliable more or less. Since you are asking about the best one, I'd recommend you to check this one http://moneyonlineslots.com/de/slots-by-themes/hulk-slots-de/
. There are themed slots and its review. As a fan of comics I attached a website with Hulk slots, but also you can find there anything you want beginning with classic slots and up to modern multi progressive ones.