Depending on how close I want to get, how much background to include, how much detail in the face to show while still being flattering,and how I want the OOF area, my choices are the 50 Lux ASPH, or the current 90 2.8 Elmarit.
This is what I also liked & still do on film, I adjust my positioning for the crop.
Basically, you really need to tell us what look you like in a portrait and how you compose it for a good suggestion from us.
Best,
Ray