Sharpest 40-45mm landscape lens

This is getting off topic, but I have to say this. I cannot agree with the suggestion that the 12-40mm is too big or heavy, and therefore a show stopper just for that, even when everything else is superb. The M43 philosophy is about being smaller without giving up much in quality. "Smaller" is relative to the DSLRs.

Those complaining about its size and weight should check the specs of the DSLR zooms with equivalent speed, FL range, IQ, AF speed and accuracy! Also consider their prices. Then they will realise what a godsend this amazing lens is. M43 users are so lucky to have this zoom, and of course the Sigma 60mm. On the other hand, I can understand the different view point of people who came from compacts and iPhones, but they should also consider the broader needs of people who are enthusiasts on this forum. For me, a 70 year old, I find it no problem at all taking a E-M5 with this zoom permanently mounted every where, and I would take another E-M5 most times when I need to change lenses for more serious shooting, ie only when I need longer reach. There is little need to use the primes in its range. So, it is much lighter, smaller, cheaper, and as good or better in IQ than going out with the 12mm, 14mm, 15mm, 17mm, 19mm, 20mm, 25mm and also a 40mm, 32mm, 28mm, 22mm ...

Regarding OP's needs, I believe the 45mm is the best overall, being cheap but excellent in IQ, versatile, and fast but any of the other M43 lenses from 40mm to 60mm would be fine too simply because they are all good lenses. M43 has really great native AF lenses and choices in this "portrait" range (but little quality in the wide angle range, and no prime lenses at all in the ultra wide range).