The BenQ XL2420T seems to be a popular 24" monitor. It is 120hz and supports 3d Vision 2, but requires you to buy the kit separately. The BenQ XL2420TX comes with the emitter and glasses built in.
The ASUS VG236HE is 23", supports 3D Vision 1 with the ASUS VG236H with the build in emitter and glasses. It does not support lightboost, so I'd be more inclined to go with the BenQ.