You should be choosing your lenses based on the ability of that lens to fulfill a specific photographic need, and not on which specific lens is sharpest. For example, you are correct that the EF-M 32mm f/1.4 is the sharpest lens in the lineup, but it is utterly worthless for photographing birds in flight. It is also a pretty poor choice for handheld video.
Second, many of the EF-M lenses suffer from sample variation issues. The zooms tend to be more problematic and the EF-M 15-45mm is by far the worst offender.
Finally, there is more to optical quality than just sharpness. While the EF-M 32mm is sharper than the Sigma 30mm, the Sigma has better bokeh. Someone shooting landscapes would prefer the Canon while someone shooting portraits would prefer the Sigma.
These lenses tend to have good optical quality and low sample variation:
- EF-M 32mm f/1.4
- EF-M 22mm f/2.0
- EF-M 28mm f/3.5 Macro IS
- EF-M 11-22mm f/4.-5.6 IS
- Sigma EF-M 16mm f/1.4
- Sigma EF-M 30mm f/1.4
- Sigma EF-M 56mm f/1.4
Some comments on the above lenses.... A good copy of the EF-M 22mm will be a bit better optically than a good copy of the 11-22mm, but they really serve different purposes and a case can be made for owning both. The 32mm is sharper than the 30mm, but the 30mm has better bokeh. While the 28mm is the only macro lens in the lineup, it is an awkward focal length for most typical macro uses and the aperture is a bit slow for general use. Even though is tends to be quite sharp, opinions on the 28mm tend to be quite polarized. If you are shooting handheld video, only two of the above lenses have stabilization.
Honorable mention goes to these lenses:
- Viltrox EF-M 23mm f/1.4
- Viltrox EF-M 33mm f/1.4
- Viltrox EF-M 56mm f/1.4
Theses lenses are not quite as good as the comparable alternatives above, but they are still optically better than the kit zooms and are quite inexpensive.
The following zooms will range from OK to horrendous depending on your copy:
- EF-M 15-45mm f/3.5-6.6 IS
- EF-M 18-55mm f/3.5-5.6 IS (discontinued)
- EF-M 18-150mm f/3.5-6.3 IS
- EF-M 55-200mm f/4.5-6.3 IS
Good copies are quite serviceable, but none of these zooms are lenses that will make you go "wow". Given the amount of sample variation, ranking them would be a challenge, but I would not call the 18-55mm the worst of the bunch. That award probably goes to the 15-45mm, but most people tend to prefer the wider 15mm view over the 18mm wide end of the other lenses.
The only other autofocus EF-M mount lens not included in the above lists is the Tamron 18-200mm f/3.5-6.3 IS. This lens is discontinued and has had multiple firmware issues with previous M system bodies. Given the previous firmware issues and lack of any future updates, I would not recommend this lens. Also, most people tend to prefer the size and optical quality of the EF-M 18-150mm over the Tamron 18-200mm.
That's it. A total of 15 autofocus EF-M lenses, with two being discontinued. If you want to go further, there is the entire catalog of EF and EF-S glass that can be adapted. Also, there are numerous third party, manual focus lenses in EF-M mount as well as most old manual focus SLR lenses from any mount being adaptable to the M system.