When there's enough light and room, the 85mm seems to be a better choice. In addition to better perspective already mentioned by @Itai, the narrow angle of view means that your shot will include less background, which means the bokeh will be smoother for same DOF (because there are less background objects to smear across the same area).
Portrait/wedding/boudoir photographer Neil van Niekerk recently blogged about this and has similar advice: try first using your longest focal length as far as you have to, and go wider only if you can't get your composition otherwise.
But to be really sure what suits your style, just try both lenses with same model and setup and see which you like more.