Sony/Minolta 135mm STF on an A900/A850. Also called "The cream machine".
But in theory, most modern lenses will produce good bokeh (unless the lens design is really off) so long as you know how to properly blur the background using basic technique.
Actually, quite a few n00bs would buy any lens or body if the salesperson tells them "All pro pictures have bokeh, this combo the best for bokeh!" just to move a 1DsMkIV and 85 f/1.2L