Erlau. They dress like Hassidim and they have a rebbe, who holds a tisch, but their traditions and minhagim are Chassam Sofer strictly (In fact, the Erlauer ravs are from the direct line of the Chassam Sofer, and their surname is in fact, Sofer.). They use Ashkenaz siddur, and their culture is an Oberlander culture.
You'll also find, if you hang out with the Erlau community, that they tend to be much more sophisticated and worldly than regular Hassidim are. Regular Hassidim are nice, sweet folks, but very simple and naive, whilst Erlau people, while also sweet and kind, seem quite educated. Erlau has selectively adopted a few Hassidishims, but haven't betrayed their authentic traditions the way other Oberlander groups have.