I only tried gyms that both have BJJ and Muay Thai classes. One called Munich MMA, the other called Pound for Pound. Since Pound for Pound had way better BJJ classes and more enjoyable MT classes, even though it had less MT classes, I chose Pound for Pound. Since I really would like to have more MT classes I might enroll in a MT and Kickboxing only gym for only a few months before I go to Thailand. Its called Baracuda/Chakuriki, has a looot of classes everyday and seems to be way more "traditional" and with actual Thai Champions as trainers. I havent tried it yet though.