I have the 35/1.4, Zeiss Tuite 50/2.8 makro, 56 APD/1.2, 16/1.4 and the 18-55/2.8-4. I also have a Nikon mount Zeiss Planar 85/1.4 with an adapter.
My photography tends to be more documentary (candid images of people who are engaged in some way, externally or internally) and because I want to be unobtrusive (not "sneaky" but also not "in your face"), the Xpro1 is the best platform I have used. Much of my work is in lower light, so fast lenses are important. My subjects are almost always people and sometimes also dogs.
The 35/1.4 is the best all around and can be had for a great price. This lens draws very well and the focal length is very handy--long enough to use for portraits, wide enough to photograph most things. If you could have only one lens, this is a good choice.
The 56 APD is expensive, let's in less light than the regular version and doesn't focus as well on the newer Fujis (I use the XPRO 1, so either would focus slower for me). I was lucky enough to get a great deal on it. It renders significantly better than the non-APD version, so for me it is well worth the trade-offs. It is not quite as good as the Zeiss 85/1.4 Planar (but what is?), but it beats the Canon 85/1.2 and the Nikon 85/1.4, which are both fine lenses--the regular 56/1.2 is not as good as these two. A portrait lens isn't as versatile as a normal, but what it does, it does very well.
The sweet sixteen, 16/1.4, is a fantastic lens and fairly new to me. The 16mm (like a 24mm in full frame) sits at the sweet spot between very wide and ultra wide. For photographing people, it is still pretty easy to take normal looking images without having to be extra careful, the way you do with an ultra wide--not to say you can be careless, but it can be used quickly once you are used to it. The 23 is probably more practical and much easier to use, but if I want wider than the 35, I want more width than the 23 or even the 18 will give me. The 16 hits the spot. It also combines a fast aperture and great close focus ability (down to 6"!). These two characteristics give it the ability to deliver very unique images which you can't really get otherwise. Wide images with shallow depth of field to separate subjects and draw the viewers attention while providing a significant amount of context--fabulous!
The 18-55/2.8-4 is a versatile lens and for many it would be a great "if I only had one lens" choice. I prefer primes. For my work, I often need faster lenses. But if I know I will be in daylight or working with studio lights (and hence stopped down), this is a handy lens. I could live without f1.2 at the portrait end and even without f1.4 (although I do use them), but I wouldn't want to give up f2.0. I tend to need f1.4 a lot at the normal end (low light) and I want something wider and faster at the wide end (hence the 16mm). So this is the lens I could most easily part with. But quickly changing situations in good light, not to mention the light weight given its versatility, make this a nice lens to have.
The Zeiss 50mm is a great lens, but I find f2.8 limiting, which makes it hard to justify the weight in the bag. The 56mm is far more likely to hold the portrait lens spot. This is a superior macro lens, going to 1:1 if needed. It draws very well and is a great portrait lens to f2.8, which is fast enough for most portrait needs. But for the type of work I tend to do, the 16 is great for close ups (not macro, but close enough for most purposes) and the 56 APD edges it out for portraits. And both beat it for low light. I do find myself bringing it out more in the studio or for images of objects (or for real macro photos), but not as much in the field anymore.
So my tendency is to take just one lens (whichever seems appropriate or fun) or, if I need versatility, three: 16, 35 and 56. This trio is, I think, the perfect combination for my way of working out of a bag.
