Located in the basement of Iron Fitness, this no-frills gym has just enough room for a ring, some bags and a few bikes. But what it lacks in space and slickness, it more than makes up for in a superior workout. Wisecracking instructors take you through a fast-paced circuit session that includes everything from ring and bag work to heavy rope training and old-fashioned jumping jacks. Tip: The boxing gym has a basic bathroom, but you have access to nicer facilities (including a shower) upstairs.
Pricing: Membership only. $119/month for unlimited classes. First class is free.