Quadrangle Recreational Athletic Center

Great place to come and play basketball with friends. They do have a decent amount if cardio machines but the weight room is lacking and machines are old. If you want to play squash or racquetball, they also have many courts inside. Basketballs are sometimes a little deflated though.
Much less crowded than the MAC near Harvard square.

Equipment: six treadmills, one stair stepper, and a bunch of ellipticals. Weight room downstairs has machines but no freeweights or dumbbells. Some squash courts, a basketball court, and a couple rooms set up for martial arts.
Overall, the vibe is super laid back, and I’ve never had to wait to use something, cardio or weights.
Beware, though, there are no TVs anyway, and only a beatup boombox downstairs, so best to bring your own entertainment.