Currently 52/38 up front and 13-28 freewheel in the back on my mildly retro modded PX10.
New Mercian touring bike will be 50/34 and 11-28 in back. It's enough for me.
My 80s Specialissima was 52/42 and 14-27 5 speed freewheel in back. It was OK for loaded touring then but I am no longer 19 and race fit.