Ooh tough call. I would say overall, the 16-35MK II. It works flawlessly, silently, instantly, and is extremely sharp wide open. The wide end for landscapes and fun portraits and the long end (35mm) for normalish shots. It just has a ton of uses.
same here, tough call but I think the 16-35 mk2 except i love it more on aps-h for a walk around lens giving 20-48mm and corner to corner sharp images wide open
my other favourite lens is my sigma 85mm f1.4