There is nothing like off camera flash.
Off camera flashes can open up a whole new world to a photographer. One can add in the multitude of modifiers out there (snoots, grids, gels, umbrellas: shoot-through and reflective, diffusers, reflectors, gobos, etc.) and the creative opportunities really become endless. For now just my umbrella (reflective and shoot-through), SB900 Flash and my SU800 Cammander unit are already working wonders for me.