I know it's mentioned frequently already in this thread.....but, I got out of photography for some time. I didn't even have any camera bodies to speak of for 7 years. I STILL kept my CY 35-70 f/3.4. I figured after buying it and selling it 4-5 times, I figured I'd keep it just in case. It's my number 1 pick.
It's an optical marvel. I find it hard to believe that there is a (technically/optically) better fast fifty from any manufacturer. Based simply on the fact that this lens is already razor sharp across most of the frame wide open (although not in the extreme corners where the ZA 50/1.4 is sharper), has negligible CA and a very soft bokeh (behind the plane of focus). I can't see any significant way this lens can be improved, although no lens is perfect. I have the Sony ZA 50/1.4 and whilst it has some advantages over the GM 50/1.2 (better at infra red, sharper in the extreme corners but less sharp mid frame) they are generally inconsequential.
#2: Leica Summilux-R 80
I've had the same lens for about 30 years. Not bored with it yet, especially on mirrorless bodies where I can now get the best from it compared to the marginal focusing accuracy on (D)SLRs where focus shift and other problems could effect the results. It's not a general purpose lens but if shooting people it is pretty hard to beat. I normally use it wide open but maybe 1/2 stop down in very harsh lighting where CA can be more noticeable. This lens and the Sony GM 50/1.2 are my two go-to lenses for people pics.
#3: Leica APO-Summicron-R 180/2
Optically it's one of the best lenses I own and virtually aberration free wide open, despite being about 27 years old. There genuinely is no reason to stop down aside from wanting more depth of field. It's a gem, although it is about 2.5Kg so is a bit of a commitment if dragging it around all day.
