Wayne, what a fun and refreshing thread. After reading for the umpteenth time questions like Biogon or Summilux, my head starts to hurt 😀
Here's my list:
On RF:
*Any* Zuiko-bearing RF that you can get for fifty bucks will have no trouble wow-ing anyone with decent taste.
Fed 50/3.5.
As said frequently, any good copy of Jupiter whatever, I have J8, J12, and J9.
Konica C35, this little guy has that special f2.8 lens that is really special.
SLR:
*Any* Zuiko that you can get for fifty bucks will have no trouble wow-ing anyone with decent taste 😀
Konica AR 50mm (both 1.4 and 1.7 will wow you).
Chinon 50mm/1.9 will wow you.
And the stable of CZ Jena M42 optics like the Biotar 58/2, some flektogon on a good day can be had for almost fifty bucks 😛
Don't overlook the super cute Industar 50-2 (clone of Tessar 50/3.5).
SMC Takumar 200/4 is quite awesome.
Tamron 28/2.5, it's very good.
Lastly, when you see a blue moon and you held your gaze just at the right angle on the monitor when you bid on the 'bay, you can get a Zeiss Planar T* 50/1.7 for fifty bucks, now that lens will wow anyone. period.