Bikram Hot Yoga in Rockville is amazing.
The studio was completely renovated a few years ago and it is the cleanest most well designed hot yoga space I’ve ever seen. (Note, I moved to DC from California, so I was impressed by Bay Area standards.) They have several different types of classes, but I absolutely love the original 90 minute Bikram series. I feel like I can stand taller after each class. I would go daily if I could.