Someonenameddavid is probably right about he M6, but I still like the older cameras better. The M4 is my favorite, and has come way done in price lately (pristine ones are still high).
Mine is the less highly regarded M4-2, and I'm perfectly happy with it (and I've had about all of them over the years); I take it some M4-2's are better or worse than others. I kept it over an M4 because at that time I needed the hot shoe. I've often regretted that decision, but have to say that this M4-2 has been the best camera I've ever owned.
The M6 is a nice camera and extremely popular (and newer, which does make a difference). Still, the rangefinder patch flare bothered me on mine. The M4-2's also are not as good in this regard as the M4 and earlier, but mine has always seemed fine. Models earlier than the M4 often are showing their age in the rangefinder system, but can be wonderful cameras too.
The modern MP's and variants (something I haven't had) are probably the best of all if you really do want a meter. I suppose those are still expensive.