Its a thought choice as they are all different for different purposes...
The 16-35mm f2.8 GM is stellar edge to edge, I used it recently for some property photography and it performs as expected. It is also not the large/heavy considering its a GM lens.
The 85mm f1.4 GM is the choice for portraits along size the newly acquired Zeiss 55mm f1.8, both are excellent.
The 24-70mm f2.8 GM is a real work horse of a lens, can easily use it for most applications and probably a good single lens solution.
I haven't used the 70-200mm f2.8 GM + 1.4x TC as much as the others, but again its stellar however the sharpness isnt much different from the f4 G version.
If I had to pick just one lens it would be a hard choice, probably end up being between the Zeiss 55mm f1,8 or the 24-70mm f2.8 GM