I bought recently an Olympus E-M5 and have started experimenting with manual lenses on it. I'm a Pentax user and have some Takumars, which work beautifully regarding manual focusing. Some are excellent optically, some not so much. My PK mount lenses are mostly either of the DA series (meaning no aperture ring) or optically sub-par, so they're not optimal.
So, excluding the M42 and PK mounts, which lens mount lenses (or even individual lenses) would you suggest worth getting?
In order to make sense, the lenses should be optically good and reasonably priced. Smallish size (shortish flange registration length) would also be a bonus.
Any suggestions? I suspect not many Leica-M lenses are reasonably priced. And while Leica-R lenses may be cheaper (or are they?), they aren't exactly small.