Originally posted by hcc You asked a a hard one. There is no single best lens. It will depend upon yourself, what you like to shoot, how you like to shoot and what you expect.
I can simply share my own experience for a prime for portraits, landscape and as a walking around lens. I have one lens that fits the bill (for me): the Voigtlander Nokton 58mm f1.4.
It is a MF lens, metallic and very sturdy, superb IQ. Why it is my fav for the job? Because the VL58mm gives me the best outcome for all type of weather, incl. fogg, smoke, smogg and appalling lighting conditions. It works for me great and it is not bad at portrait, although I prefer the FA77mm for portrait.
There is no simple answer to your query and I can only share my experience.
+1!
Happy (and a little surprised) to see that comment. The Nokton 58mm is my favorite lens (and I own a few). I can't wait to use it on the FF digital; I love it on my film bodies.
But for all around general purpose I think most are best served by a 50mm. I'm still consistently impressed by my humble ol' A 50mm 1.7. There's no beating the bang you get for your buck.
I tried to pare down my kit to the bare minimum on a recent trip. I left the beautiful but big Nokton at home and brought my 50mm and a 20mm (Voigtlander Color Skopar) along with my K1000. I barely used the 20mm.
On digital I get a lot of mileage out of my DA 21mm for trips and whatnot, but it doesn't accel for portraits (let alone low-light) like a 50mm.