Other than side-bends, what is a great exercise for the obliques?

Other than side-bends a great exercise for the obliques is the knee-up with rotation.  Perform the knee-up with rotation by following the technique described below. Lie with your back on the floor or on a flat bench with your hips bent at a 90 degree angle.  Next, grab a stable object for support, and while keeping the hips bent at a 90 degree angle, extend the legs into the air.  Make sure to draw-in your abs and contract your glutes.  Last, lift your hips off of the floor or bench, reaching your feet up towards the ceiling.  As you move your legs upward, rotate your hips and legs slightly in one direction like a corkscrew.  Slowly return to the starting position and repeat as necessary.  Alternatively, if this exercise is too challenging,  a cable chop is an exercise that will also target the obliques.