I've got a ZM 2/85 that I use a fair bit, though not as much as the 50 or 35, and a 4/135 Elmar (not the tele-elmar) that I've actually used much more than I expected. Both a lovely lenses, though they have different looks of course, and are far more useful on the M9 than I excpecetd (this applies more to the 135 of course).
Mike