Prepare to get your butt kicked!
Spinning classes on traditional indoor bikes is tough, but the RealRyders used at First Wind take it to another level. RealRyder bikes mimic riding a road bike since they allow you to lean, steer, and turn.
They offer a handful of different class types, including barre and barre/cycling combos, and one of the cycling classes follows a "virtual ride" projected on the large screen at the front of class. Sign up online in advance to reserve your spot.
If you don't have your own SPD-compatible shoes (or forget them at home), you can borrow from the studio or simply wear regular tennis shoes.
Since it's a specialty fitness studio, it's not cheap, but their prices are a little lower than what I've seen advertised for That Other Cycling Studio across town (at least for now).