The original Korg A single-manual drawbar organ that sounded more like a Hammond than some of the Hammonds did. Solid state, simulated the tonewheel sound and allowed for on-the-fly mods with the drawbars. A portable alternative to the B
Vintage Korg Analog clonewheel - At the time, it sounded better than that Hammond clones did. Still a decent instrument, if you can find one, and if you have a Ventilator to give your the Leslie effects. Dual manuals are cool, too.
The Roland VK-7 uses modelling and samples of Hammond B3's to recreate the Hammond sound. The Roland also includes some extra sound patches, horns, strings, etc. Decent organ sounds, bu the extra sounds aren't worth much. Except for the drawbar capabilities, I think Roland's samples in its synths (especially the Fantoms) are a better.