I liked the Oly 18, but only because it was inexpensive and rendered a more classic look -- not nearly as crisp as the Oly 24/2. I borrowed and liked the Oly 50/1.2, again for it's unique look. My absolute favorites were the Oly 24/2, the Leica R 35 Lux, and the Leica R 80 Lux. I never got to try a Leica 50 Lux, but suspect it would feel the same as the 35 and 80, and if it did would make my ideal MF trio, with the Oly 24/2 rounding out a foursome. If you want a really crisp shift lens, the C/Y Zeiss 35 is awesome.
My issue now is my aging eyes -- I really need AF for hand-held work. So the MF lenses are not for me anymore unless they're specialty, like the TSE's or a killer macro.