I use an OM1 and OM2 as my main shooters. B&W in one, colour in t'other. I have 24mm (sigma filtermatic) 35mm f2.8, 50mm f1.8, 135mm f4, 35-70 f4 zoom, 70-150 f4 zoom and a sigma 70-210 zoom.
For me, the lens that nearly always gets taken out is.......
the 35-70 f4 zoom. Not the smallest zoom - there is another zuiko zoom the 35-70 f3.5-4.5 which I don't have, but I get on really well with the 35-70 f4. My version is certainly sharp enough - to the extent I don't notice any difference between that and the 50 or 35mm primes in terms of image quality.
No 2 lens for me is the standard 50mm 1.8. Check out my pix. virtually all shot with the 35-70