In the past year or so, I have made Yoga my primary form of exercise. If you didn't think Yoga could make you sweat, check out a Vinyasa class.
All the instructors here are very nice, and well-experienced. There are classes for all levels ranging from 1-3 (3 being on the hard side). A lot of of the regulars are pros meaning it's normal to see people doing headstands. They also bring in special instructors from out of town to keep the classes exciting. My favorite regular teachers are Eric and Rachel.